diff options
Diffstat (limited to 'lib/libfdt')
| -rw-r--r-- | lib/libfdt/fdt.c | 335 | ||||
| -rw-r--r-- | lib/libfdt/fdt_addresses.c | 101 | ||||
| -rw-r--r-- | lib/libfdt/fdt_empty_tree.c | 38 | ||||
| -rw-r--r-- | lib/libfdt/fdt_overlay.c | 867 | ||||
| -rw-r--r-- | lib/libfdt/fdt_ro.c | 859 | ||||
| -rw-r--r-- | lib/libfdt/fdt_rw.c | 500 | ||||
| -rw-r--r-- | lib/libfdt/fdt_strerror.c | 60 | ||||
| -rw-r--r-- | lib/libfdt/fdt_sw.c | 384 | ||||
| -rw-r--r-- | lib/libfdt/fdt_wip.c | 94 | ||||
| -rw-r--r-- | lib/libfdt/libfdt.mk | 19 | ||||
| -rw-r--r-- | lib/libfdt/libfdt_internal.h | 192 |
11 files changed, 3449 insertions, 0 deletions
diff --git a/lib/libfdt/fdt.c b/lib/libfdt/fdt.c new file mode 100644 index 0000000..9fe7cf4 --- /dev/null +++ b/lib/libfdt/fdt.c @@ -0,0 +1,335 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +/* + * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks + * that the given buffer contains what appears to be a flattened + * device tree with sane information in its header. + */ +int32_t fdt_ro_probe_(const void *fdt) +{ + uint32_t totalsize = fdt_totalsize(fdt); + + if (can_assume(VALID_DTB)) + return totalsize; + + /* The device tree must be at an 8-byte aligned address */ + if ((uintptr_t)fdt & 7) + return -FDT_ERR_ALIGNMENT; + + if (fdt_magic(fdt) == FDT_MAGIC) { + /* Complete tree */ + if (!can_assume(LATEST)) { + if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) + return -FDT_ERR_BADVERSION; + if (fdt_last_comp_version(fdt) > + FDT_LAST_SUPPORTED_VERSION) + return -FDT_ERR_BADVERSION; + } + } else if (fdt_magic(fdt) == FDT_SW_MAGIC) { + /* Unfinished sequential-write blob */ + if (!can_assume(VALID_INPUT) && fdt_size_dt_struct(fdt) == 0) + return -FDT_ERR_BADSTATE; + } else { + return -FDT_ERR_BADMAGIC; + } + + if (totalsize < INT32_MAX) + return totalsize; + else + return -FDT_ERR_TRUNCATED; +} + +static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off) +{ + return (off >= hdrsize) && (off <= totalsize); +} + +static int check_block_(uint32_t hdrsize, uint32_t totalsize, + uint32_t base, uint32_t size) +{ + if (!check_off_(hdrsize, totalsize, base)) + return 0; /* block start out of bounds */ + if ((base + size) < base) + return 0; /* overflow */ + if (!check_off_(hdrsize, totalsize, base + size)) + return 0; /* block end out of bounds */ + return 1; +} + +size_t fdt_header_size_(uint32_t version) +{ + if (version <= 1) + return FDT_V1_SIZE; + else if (version <= 2) + return FDT_V2_SIZE; + else if (version <= 3) + return FDT_V3_SIZE; + else if (version <= 16) + return FDT_V16_SIZE; + else + return FDT_V17_SIZE; +} + +size_t fdt_header_size(const void *fdt) +{ + return can_assume(LATEST) ? FDT_V17_SIZE : + fdt_header_size_(fdt_version(fdt)); +} + +int fdt_check_header(const void *fdt) +{ + size_t hdrsize; + + /* The device tree must be at an 8-byte aligned address */ + if ((uintptr_t)fdt & 7) + return -FDT_ERR_ALIGNMENT; + + if (fdt_magic(fdt) != FDT_MAGIC) + return -FDT_ERR_BADMAGIC; + if (!can_assume(LATEST)) { + if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) + || (fdt_last_comp_version(fdt) > + FDT_LAST_SUPPORTED_VERSION)) + return -FDT_ERR_BADVERSION; + if (fdt_version(fdt) < fdt_last_comp_version(fdt)) + return -FDT_ERR_BADVERSION; + } + hdrsize = fdt_header_size(fdt); + if (!can_assume(VALID_DTB)) { + + if ((fdt_totalsize(fdt) < hdrsize) + || (fdt_totalsize(fdt) > INT_MAX)) + return -FDT_ERR_TRUNCATED; + + /* Bounds check memrsv block */ + if (!check_off_(hdrsize, fdt_totalsize(fdt), + fdt_off_mem_rsvmap(fdt))) + return -FDT_ERR_TRUNCATED; + } + + if (!can_assume(VALID_DTB)) { + /* Bounds check structure block */ + if (!can_assume(LATEST) && fdt_version(fdt) < 17) { + if (!check_off_(hdrsize, fdt_totalsize(fdt), + fdt_off_dt_struct(fdt))) + return -FDT_ERR_TRUNCATED; + } else { + if (!check_block_(hdrsize, fdt_totalsize(fdt), + fdt_off_dt_struct(fdt), + fdt_size_dt_struct(fdt))) + return -FDT_ERR_TRUNCATED; + } + + /* Bounds check strings block */ + if (!check_block_(hdrsize, fdt_totalsize(fdt), + fdt_off_dt_strings(fdt), + fdt_size_dt_strings(fdt))) + return -FDT_ERR_TRUNCATED; + } + + return 0; +} + +const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len) +{ + unsigned int uoffset = offset; + unsigned int absoffset = offset + fdt_off_dt_struct(fdt); + + if (offset < 0) + return NULL; + + if (!can_assume(VALID_INPUT)) + if ((absoffset < uoffset) + || ((absoffset + len) < absoffset) + || (absoffset + len) > fdt_totalsize(fdt)) + return NULL; + + if (can_assume(LATEST) || fdt_version(fdt) >= 0x11) + if (((uoffset + len) < uoffset) + || ((offset + len) > fdt_size_dt_struct(fdt))) + return NULL; + + return fdt_offset_ptr_(fdt, offset); +} + +uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) +{ + const fdt32_t *tagp, *lenp; + uint32_t tag; + int offset = startoffset; + const char *p; + + *nextoffset = -FDT_ERR_TRUNCATED; + tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE); + if (!can_assume(VALID_DTB) && !tagp) + return FDT_END; /* premature end */ + tag = fdt32_to_cpu(*tagp); + offset += FDT_TAGSIZE; + + *nextoffset = -FDT_ERR_BADSTRUCTURE; + switch (tag) { + case FDT_BEGIN_NODE: + /* skip name */ + do { + p = fdt_offset_ptr(fdt, offset++, 1); + } while (p && (*p != '\0')); + if (!can_assume(VALID_DTB) && !p) + return FDT_END; /* premature end */ + break; + + case FDT_PROP: + lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp)); + if (!can_assume(VALID_DTB) && !lenp) + return FDT_END; /* premature end */ + /* skip-name offset, length and value */ + offset += sizeof(struct fdt_property) - FDT_TAGSIZE + + fdt32_to_cpu(*lenp); + if (!can_assume(LATEST) && + fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 && + ((offset - fdt32_to_cpu(*lenp)) % 8) != 0) + offset += 4; + break; + + case FDT_END: + case FDT_END_NODE: + case FDT_NOP: + break; + + default: + return FDT_END; + } + + if (!fdt_offset_ptr(fdt, startoffset, offset - startoffset)) + return FDT_END; /* premature end */ + + *nextoffset = FDT_TAGALIGN(offset); + return tag; +} + +int fdt_check_node_offset_(const void *fdt, int offset) +{ + if (!can_assume(VALID_INPUT) + && ((offset < 0) || (offset % FDT_TAGSIZE))) + return -FDT_ERR_BADOFFSET; + + if (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE) + return -FDT_ERR_BADOFFSET; + + return offset; +} + +int fdt_check_prop_offset_(const void *fdt, int offset) +{ + if (!can_assume(VALID_INPUT) + && ((offset < 0) || (offset % FDT_TAGSIZE))) + return -FDT_ERR_BADOFFSET; + + if (fdt_next_tag(fdt, offset, &offset) != FDT_PROP) + return -FDT_ERR_BADOFFSET; + + return offset; +} + +int fdt_next_node(const void *fdt, int offset, int *depth) +{ + int nextoffset = 0; + uint32_t tag; + + if (offset >= 0) + if ((nextoffset = fdt_check_node_offset_(fdt, offset)) < 0) + return nextoffset; + + do { + offset = nextoffset; + tag = fdt_next_tag(fdt, offset, &nextoffset); + + switch (tag) { + case FDT_PROP: + case FDT_NOP: + break; + + case FDT_BEGIN_NODE: + if (depth) + (*depth)++; + break; + + case FDT_END_NODE: + if (depth && ((--(*depth)) < 0)) + return nextoffset; + break; + + case FDT_END: + if ((nextoffset >= 0) + || ((nextoffset == -FDT_ERR_TRUNCATED) && !depth)) + return -FDT_ERR_NOTFOUND; + else + return nextoffset; + } + } while (tag != FDT_BEGIN_NODE); + + return offset; +} + +int fdt_first_subnode(const void *fdt, int offset) +{ + int depth = 0; + + offset = fdt_next_node(fdt, offset, &depth); + if (offset < 0 || depth != 1) + return -FDT_ERR_NOTFOUND; + + return offset; +} + +int fdt_next_subnode(const void *fdt, int offset) +{ + int depth = 1; + + /* + * With respect to the parent, the depth of the next subnode will be + * the same as the last. + */ + do { + offset = fdt_next_node(fdt, offset, &depth); + if (offset < 0 || depth < 1) + return -FDT_ERR_NOTFOUND; + } while (depth > 1); + + return offset; +} + +const char *fdt_find_string_(const char *strtab, int tabsize, const char *s) +{ + int len = strlen(s) + 1; + const char *last = strtab + tabsize - len; + const char *p; + + for (p = strtab; p <= last; p++) + if (memcmp(p, s, len) == 0) + return p; + return NULL; +} + +int fdt_move(const void *fdt, void *buf, int bufsize) +{ + if (!can_assume(VALID_INPUT) && bufsize < 0) + return -FDT_ERR_NOSPACE; + + FDT_RO_PROBE(fdt); + + if (fdt_totalsize(fdt) > (unsigned int)bufsize) + return -FDT_ERR_NOSPACE; + + memmove(buf, fdt, fdt_totalsize(fdt)); + return 0; +} diff --git a/lib/libfdt/fdt_addresses.c b/lib/libfdt/fdt_addresses.c new file mode 100644 index 0000000..c40ba09 --- /dev/null +++ b/lib/libfdt/fdt_addresses.c @@ -0,0 +1,101 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2014 David Gibson <david@gibson.dropbear.id.au> + * Copyright (C) 2018 embedded brains GmbH + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +static int fdt_cells(const void *fdt, int nodeoffset, const char *name) +{ + const fdt32_t *c; + uint32_t val; + int len; + + c = fdt_getprop(fdt, nodeoffset, name, &len); + if (!c) + return len; + + if (len != sizeof(*c)) + return -FDT_ERR_BADNCELLS; + + val = fdt32_to_cpu(*c); + if (val > FDT_MAX_NCELLS) + return -FDT_ERR_BADNCELLS; + + return (int)val; +} + +int fdt_address_cells(const void *fdt, int nodeoffset) +{ + int val; + + val = fdt_cells(fdt, nodeoffset, "#address-cells"); + if (val == 0) + return -FDT_ERR_BADNCELLS; + if (val == -FDT_ERR_NOTFOUND) + return 2; + return val; +} + +int fdt_size_cells(const void *fdt, int nodeoffset) +{ + int val; + + val = fdt_cells(fdt, nodeoffset, "#size-cells"); + if (val == -FDT_ERR_NOTFOUND) + return 1; + return val; +} + +/* This function assumes that [address|size]_cells is 1 or 2 */ +int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset, + const char *name, uint64_t addr, uint64_t size) +{ + int addr_cells, size_cells, ret; + uint8_t data[sizeof(fdt64_t) * 2], *prop; + + ret = fdt_address_cells(fdt, parent); + if (ret < 0) + return ret; + addr_cells = ret; + + ret = fdt_size_cells(fdt, parent); + if (ret < 0) + return ret; + size_cells = ret; + + /* check validity of address */ + prop = data; + if (addr_cells == 1) { + if ((addr > UINT32_MAX) || (((uint64_t) UINT32_MAX + 1 - addr) < size)) + return -FDT_ERR_BADVALUE; + + fdt32_st(prop, (uint32_t)addr); + } else if (addr_cells == 2) { + fdt64_st(prop, addr); + } else { + return -FDT_ERR_BADNCELLS; + } + + /* check validity of size */ + prop += addr_cells * sizeof(fdt32_t); + if (size_cells == 1) { + if (size > UINT32_MAX) + return -FDT_ERR_BADVALUE; + + fdt32_st(prop, (uint32_t)size); + } else if (size_cells == 2) { + fdt64_st(prop, size); + } else { + return -FDT_ERR_BADNCELLS; + } + + return fdt_appendprop(fdt, nodeoffset, name, data, + (addr_cells + size_cells) * sizeof(fdt32_t)); +} diff --git a/lib/libfdt/fdt_empty_tree.c b/lib/libfdt/fdt_empty_tree.c new file mode 100644 index 0000000..49d54d4 --- /dev/null +++ b/lib/libfdt/fdt_empty_tree.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2012 David Gibson, IBM Corporation. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +int fdt_create_empty_tree(void *buf, int bufsize) +{ + int err; + + err = fdt_create(buf, bufsize); + if (err) + return err; + + err = fdt_finish_reservemap(buf); + if (err) + return err; + + err = fdt_begin_node(buf, ""); + if (err) + return err; + + err = fdt_end_node(buf); + if (err) + return err; + + err = fdt_finish(buf); + if (err) + return err; + + return fdt_open_into(buf, buf, bufsize); +} diff --git a/lib/libfdt/fdt_overlay.c b/lib/libfdt/fdt_overlay.c new file mode 100644 index 0000000..5c0c398 --- /dev/null +++ b/lib/libfdt/fdt_overlay.c @@ -0,0 +1,867 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2016 Free Electrons + * Copyright (C) 2016 NextThing Co. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +/** + * overlay_get_target_phandle - retrieves the target phandle of a fragment + * @fdto: pointer to the device tree overlay blob + * @fragment: node offset of the fragment in the overlay + * + * overlay_get_target_phandle() retrieves the target phandle of an + * overlay fragment when that fragment uses a phandle (target + * property) instead of a path (target-path property). + * + * returns: + * the phandle pointed by the target property + * 0, if the phandle was not found + * -1, if the phandle was malformed + */ +static uint32_t overlay_get_target_phandle(const void *fdto, int fragment) +{ + const fdt32_t *val; + int len; + + val = fdt_getprop(fdto, fragment, "target", &len); + if (!val) + return 0; + + if ((len != sizeof(*val)) || (fdt32_to_cpu(*val) == (uint32_t)-1)) + return (uint32_t)-1; + + return fdt32_to_cpu(*val); +} + +int fdt_overlay_target_offset(const void *fdt, const void *fdto, + int fragment_offset, char const **pathp) +{ + uint32_t phandle; + const char *path = NULL; + int path_len = 0, ret; + + /* Try first to do a phandle based lookup */ + phandle = overlay_get_target_phandle(fdto, fragment_offset); + if (phandle == (uint32_t)-1) + return -FDT_ERR_BADPHANDLE; + + /* no phandle, try path */ + if (!phandle) { + /* And then a path based lookup */ + path = fdt_getprop(fdto, fragment_offset, "target-path", &path_len); + if (path) + ret = fdt_path_offset(fdt, path); + else + ret = path_len; + } else + ret = fdt_node_offset_by_phandle(fdt, phandle); + + /* + * If we haven't found either a target or a + * target-path property in a node that contains a + * __overlay__ subnode (we wouldn't be called + * otherwise), consider it a improperly written + * overlay + */ + if (ret < 0 && path_len == -FDT_ERR_NOTFOUND) + ret = -FDT_ERR_BADOVERLAY; + + /* return on error */ + if (ret < 0) + return ret; + + /* return pointer to path (if available) */ + if (pathp) + *pathp = path ? path : NULL; + + return ret; +} + +/** + * overlay_phandle_add_offset - Increases a phandle by an offset + * @fdt: Base device tree blob + * @node: Device tree overlay blob + * @name: Name of the property to modify (phandle or linux,phandle) + * @delta: offset to apply + * + * overlay_phandle_add_offset() increments a node phandle by a given + * offset. + * + * returns: + * 0 on success. + * Negative error code on error + */ +static int overlay_phandle_add_offset(void *fdt, int node, + const char *name, uint32_t delta) +{ + const fdt32_t *val; + uint32_t adj_val; + int len; + + val = fdt_getprop(fdt, node, name, &len); + if (!val) + return len; + + if (len != sizeof(*val)) + return -FDT_ERR_BADPHANDLE; + + adj_val = fdt32_to_cpu(*val); + if ((adj_val + delta) < adj_val) + return -FDT_ERR_NOPHANDLES; + + adj_val += delta; + if (adj_val == (uint32_t)-1) + return -FDT_ERR_NOPHANDLES; + + return fdt_setprop_inplace_u32(fdt, node, name, adj_val); +} + +/** + * overlay_adjust_node_phandles - Offsets the phandles of a node + * @fdto: Device tree overlay blob + * @node: Offset of the node we want to adjust + * @delta: Offset to shift the phandles of + * + * overlay_adjust_node_phandles() adds a constant to all the phandles + * of a given node. This is mainly use as part of the overlay + * application process, when we want to update all the overlay + * phandles to not conflict with the overlays of the base device tree. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_adjust_node_phandles(void *fdto, int node, + uint32_t delta) +{ + int child; + int ret; + + ret = overlay_phandle_add_offset(fdto, node, "phandle", delta); + if (ret && ret != -FDT_ERR_NOTFOUND) + return ret; + + ret = overlay_phandle_add_offset(fdto, node, "linux,phandle", delta); + if (ret && ret != -FDT_ERR_NOTFOUND) + return ret; + + fdt_for_each_subnode(child, fdto, node) { + ret = overlay_adjust_node_phandles(fdto, child, delta); + if (ret) + return ret; + } + + return 0; +} + +/** + * overlay_adjust_local_phandles - Adjust the phandles of a whole overlay + * @fdto: Device tree overlay blob + * @delta: Offset to shift the phandles of + * + * overlay_adjust_local_phandles() adds a constant to all the + * phandles of an overlay. This is mainly use as part of the overlay + * application process, when we want to update all the overlay + * phandles to not conflict with the overlays of the base device tree. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_adjust_local_phandles(void *fdto, uint32_t delta) +{ + /* + * Start adjusting the phandles from the overlay root + */ + return overlay_adjust_node_phandles(fdto, 0, delta); +} + +/** + * overlay_update_local_node_references - Adjust the overlay references + * @fdto: Device tree overlay blob + * @tree_node: Node offset of the node to operate on + * @fixup_node: Node offset of the matching local fixups node + * @delta: Offset to shift the phandles of + * + * overlay_update_local_nodes_references() update the phandles + * pointing to a node within the device tree overlay by adding a + * constant delta. + * + * This is mainly used as part of a device tree application process, + * where you want the device tree overlays phandles to not conflict + * with the ones from the base device tree before merging them. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_update_local_node_references(void *fdto, + int tree_node, + int fixup_node, + uint32_t delta) +{ + int fixup_prop; + int fixup_child; + int ret; + + fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) { + const fdt32_t *fixup_val; + const char *tree_val; + const char *name; + int fixup_len; + int tree_len; + int i; + + fixup_val = fdt_getprop_by_offset(fdto, fixup_prop, + &name, &fixup_len); + if (!fixup_val) + return fixup_len; + + if (fixup_len % sizeof(uint32_t)) + return -FDT_ERR_BADOVERLAY; + fixup_len /= sizeof(uint32_t); + + tree_val = fdt_getprop(fdto, tree_node, name, &tree_len); + if (!tree_val) { + if (tree_len == -FDT_ERR_NOTFOUND) + return -FDT_ERR_BADOVERLAY; + + return tree_len; + } + + for (i = 0; i < fixup_len; i++) { + fdt32_t adj_val; + uint32_t poffset; + + poffset = fdt32_to_cpu(fixup_val[i]); + + /* + * phandles to fixup can be unaligned. + * + * Use a memcpy for the architectures that do + * not support unaligned accesses. + */ + memcpy(&adj_val, tree_val + poffset, sizeof(adj_val)); + + adj_val = cpu_to_fdt32(fdt32_to_cpu(adj_val) + delta); + + ret = fdt_setprop_inplace_namelen_partial(fdto, + tree_node, + name, + strlen(name), + poffset, + &adj_val, + sizeof(adj_val)); + if (ret == -FDT_ERR_NOSPACE) + return -FDT_ERR_BADOVERLAY; + + if (ret) + return ret; + } + } + + fdt_for_each_subnode(fixup_child, fdto, fixup_node) { + const char *fixup_child_name = fdt_get_name(fdto, fixup_child, + NULL); + int tree_child; + + tree_child = fdt_subnode_offset(fdto, tree_node, + fixup_child_name); + if (tree_child == -FDT_ERR_NOTFOUND) + return -FDT_ERR_BADOVERLAY; + if (tree_child < 0) + return tree_child; + + ret = overlay_update_local_node_references(fdto, + tree_child, + fixup_child, + delta); + if (ret) + return ret; + } + + return 0; +} + +/** + * overlay_update_local_references - Adjust the overlay references + * @fdto: Device tree overlay blob + * @delta: Offset to shift the phandles of + * + * overlay_update_local_references() update all the phandles pointing + * to a node within the device tree overlay by adding a constant + * delta to not conflict with the base overlay. + * + * This is mainly used as part of a device tree application process, + * where you want the device tree overlays phandles to not conflict + * with the ones from the base device tree before merging them. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_update_local_references(void *fdto, uint32_t delta) +{ + int fixups; + + fixups = fdt_path_offset(fdto, "/__local_fixups__"); + if (fixups < 0) { + /* There's no local phandles to adjust, bail out */ + if (fixups == -FDT_ERR_NOTFOUND) + return 0; + + return fixups; + } + + /* + * Update our local references from the root of the tree + */ + return overlay_update_local_node_references(fdto, 0, fixups, + delta); +} + +/** + * overlay_fixup_one_phandle - Set an overlay phandle to the base one + * @fdt: Base Device Tree blob + * @fdto: Device tree overlay blob + * @symbols_off: Node offset of the symbols node in the base device tree + * @path: Path to a node holding a phandle in the overlay + * @path_len: number of path characters to consider + * @name: Name of the property holding the phandle reference in the overlay + * @name_len: number of name characters to consider + * @poffset: Offset within the overlay property where the phandle is stored + * @label: Label of the node referenced by the phandle + * + * overlay_fixup_one_phandle() resolves an overlay phandle pointing to + * a node in the base device tree. + * + * This is part of the device tree overlay application process, when + * you want all the phandles in the overlay to point to the actual + * base dt nodes. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_fixup_one_phandle(void *fdt, void *fdto, + int symbols_off, + const char *path, uint32_t path_len, + const char *name, uint32_t name_len, + int poffset, const char *label) +{ + const char *symbol_path; + uint32_t phandle; + fdt32_t phandle_prop; + int symbol_off, fixup_off; + int prop_len; + + if (symbols_off < 0) + return symbols_off; + + symbol_path = fdt_getprop(fdt, symbols_off, label, + &prop_len); + if (!symbol_path) + return prop_len; + + symbol_off = fdt_path_offset(fdt, symbol_path); + if (symbol_off < 0) + return symbol_off; + + phandle = fdt_get_phandle(fdt, symbol_off); + if (!phandle) + return -FDT_ERR_NOTFOUND; + + fixup_off = fdt_path_offset_namelen(fdto, path, path_len); + if (fixup_off == -FDT_ERR_NOTFOUND) + return -FDT_ERR_BADOVERLAY; + if (fixup_off < 0) + return fixup_off; + + phandle_prop = cpu_to_fdt32(phandle); + return fdt_setprop_inplace_namelen_partial(fdto, fixup_off, + name, name_len, poffset, + &phandle_prop, + sizeof(phandle_prop)); +}; + +/** + * overlay_fixup_phandle - Set an overlay phandle to the base one + * @fdt: Base Device Tree blob + * @fdto: Device tree overlay blob + * @symbols_off: Node offset of the symbols node in the base device tree + * @property: Property offset in the overlay holding the list of fixups + * + * overlay_fixup_phandle() resolves all the overlay phandles pointed + * to in a __fixups__ property, and updates them to match the phandles + * in use in the base device tree. + * + * This is part of the device tree overlay application process, when + * you want all the phandles in the overlay to point to the actual + * base dt nodes. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off, + int property) +{ + const char *value; + const char *label; + int len; + + value = fdt_getprop_by_offset(fdto, property, + &label, &len); + if (!value) { + if (len == -FDT_ERR_NOTFOUND) + return -FDT_ERR_INTERNAL; + + return len; + } + + do { + const char *path, *name, *fixup_end; + const char *fixup_str = value; + uint32_t path_len, name_len; + uint32_t fixup_len; + char *sep, *endptr; + int poffset, ret; + + fixup_end = memchr(value, '\0', len); + if (!fixup_end) + return -FDT_ERR_BADOVERLAY; + fixup_len = fixup_end - fixup_str; + + len -= fixup_len + 1; + value += fixup_len + 1; + + path = fixup_str; + sep = memchr(fixup_str, ':', fixup_len); + if (!sep || *sep != ':') + return -FDT_ERR_BADOVERLAY; + + path_len = sep - path; + if (path_len == (fixup_len - 1)) + return -FDT_ERR_BADOVERLAY; + + fixup_len -= path_len + 1; + name = sep + 1; + sep = memchr(name, ':', fixup_len); + if (!sep || *sep != ':') + return -FDT_ERR_BADOVERLAY; + + name_len = sep - name; + if (!name_len) + return -FDT_ERR_BADOVERLAY; + + poffset = strtoul(sep + 1, &endptr, 10); + if ((*endptr != '\0') || (endptr <= (sep + 1))) + return -FDT_ERR_BADOVERLAY; + + ret = overlay_fixup_one_phandle(fdt, fdto, symbols_off, + path, path_len, name, name_len, + poffset, label); + if (ret) + return ret; + } while (len > 0); + + return 0; +} + +/** + * overlay_fixup_phandles - Resolve the overlay phandles to the base + * device tree + * @fdt: Base Device Tree blob + * @fdto: Device tree overlay blob + * + * overlay_fixup_phandles() resolves all the overlay phandles pointing + * to nodes in the base device tree. + * + * This is one of the steps of the device tree overlay application + * process, when you want all the phandles in the overlay to point to + * the actual base dt nodes. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_fixup_phandles(void *fdt, void *fdto) +{ + int fixups_off, symbols_off; + int property; + + /* We can have overlays without any fixups */ + fixups_off = fdt_path_offset(fdto, "/__fixups__"); + if (fixups_off == -FDT_ERR_NOTFOUND) + return 0; /* nothing to do */ + if (fixups_off < 0) + return fixups_off; + + /* And base DTs without symbols */ + symbols_off = fdt_path_offset(fdt, "/__symbols__"); + if ((symbols_off < 0 && (symbols_off != -FDT_ERR_NOTFOUND))) + return symbols_off; + + fdt_for_each_property_offset(property, fdto, fixups_off) { + int ret; + + ret = overlay_fixup_phandle(fdt, fdto, symbols_off, property); + if (ret) + return ret; + } + + return 0; +} + +/** + * overlay_apply_node - Merges a node into the base device tree + * @fdt: Base Device Tree blob + * @target: Node offset in the base device tree to apply the fragment to + * @fdto: Device tree overlay blob + * @node: Node offset in the overlay holding the changes to merge + * + * overlay_apply_node() merges a node into a target base device tree + * node pointed. + * + * This is part of the final step in the device tree overlay + * application process, when all the phandles have been adjusted and + * resolved and you just have to merge overlay into the base device + * tree. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_apply_node(void *fdt, int target, + void *fdto, int node) +{ + int property; + int subnode; + + fdt_for_each_property_offset(property, fdto, node) { + const char *name; + const void *prop; + int prop_len; + int ret; + + prop = fdt_getprop_by_offset(fdto, property, &name, + &prop_len); + if (prop_len == -FDT_ERR_NOTFOUND) + return -FDT_ERR_INTERNAL; + if (prop_len < 0) + return prop_len; + + ret = fdt_setprop(fdt, target, name, prop, prop_len); + if (ret) + return ret; + } + + fdt_for_each_subnode(subnode, fdto, node) { + const char *name = fdt_get_name(fdto, subnode, NULL); + int nnode; + int ret; + + nnode = fdt_add_subnode(fdt, target, name); + if (nnode == -FDT_ERR_EXISTS) { + nnode = fdt_subnode_offset(fdt, target, name); + if (nnode == -FDT_ERR_NOTFOUND) + return -FDT_ERR_INTERNAL; + } + + if (nnode < 0) + return nnode; + + ret = overlay_apply_node(fdt, nnode, fdto, subnode); + if (ret) + return ret; + } + + return 0; +} + +/** + * overlay_merge - Merge an overlay into its base device tree + * @fdt: Base Device Tree blob + * @fdto: Device tree overlay blob + * + * overlay_merge() merges an overlay into its base device tree. + * + * This is the next to last step in the device tree overlay application + * process, when all the phandles have been adjusted and resolved and + * you just have to merge overlay into the base device tree. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_merge(void *fdt, void *fdto) +{ + int fragment; + + fdt_for_each_subnode(fragment, fdto, 0) { + int overlay; + int target; + int ret; + + /* + * Each fragments will have an __overlay__ node. If + * they don't, it's not supposed to be merged + */ + overlay = fdt_subnode_offset(fdto, fragment, "__overlay__"); + if (overlay == -FDT_ERR_NOTFOUND) + continue; + + if (overlay < 0) + return overlay; + + target = fdt_overlay_target_offset(fdt, fdto, fragment, NULL); + if (target < 0) + return target; + + ret = overlay_apply_node(fdt, target, fdto, overlay); + if (ret) + return ret; + } + + return 0; +} + +static int get_path_len(const void *fdt, int nodeoffset) +{ + int len = 0, namelen; + const char *name; + + FDT_RO_PROBE(fdt); + + for (;;) { + name = fdt_get_name(fdt, nodeoffset, &namelen); + if (!name) + return namelen; + + /* root? we're done */ + if (namelen == 0) + break; + + nodeoffset = fdt_parent_offset(fdt, nodeoffset); + if (nodeoffset < 0) + return nodeoffset; + len += namelen + 1; + } + + /* in case of root pretend it's "/" */ + if (len == 0) + len++; + return len; +} + +/** + * overlay_symbol_update - Update the symbols of base tree after a merge + * @fdt: Base Device Tree blob + * @fdto: Device tree overlay blob + * + * overlay_symbol_update() updates the symbols of the base tree with the + * symbols of the applied overlay + * + * This is the last step in the device tree overlay application + * process, allowing the reference of overlay symbols by subsequent + * overlay operations. + * + * returns: + * 0 on success + * Negative error code on failure + */ +static int overlay_symbol_update(void *fdt, void *fdto) +{ + int root_sym, ov_sym, prop, path_len, fragment, target; + int len, frag_name_len, ret, rel_path_len; + const char *s, *e; + const char *path; + const char *name; + const char *frag_name; + const char *rel_path; + const char *target_path; + char *buf; + void *p; + + ov_sym = fdt_subnode_offset(fdto, 0, "__symbols__"); + + /* if no overlay symbols exist no problem */ + if (ov_sym < 0) + return 0; + + root_sym = fdt_subnode_offset(fdt, 0, "__symbols__"); + + /* it no root symbols exist we should create them */ + if (root_sym == -FDT_ERR_NOTFOUND) + root_sym = fdt_add_subnode(fdt, 0, "__symbols__"); + + /* any error is fatal now */ + if (root_sym < 0) + return root_sym; + + /* iterate over each overlay symbol */ + fdt_for_each_property_offset(prop, fdto, ov_sym) { + path = fdt_getprop_by_offset(fdto, prop, &name, &path_len); + if (!path) + return path_len; + + /* verify it's a string property (terminated by a single \0) */ + if (path_len < 1 || memchr(path, '\0', path_len) != &path[path_len - 1]) + return -FDT_ERR_BADVALUE; + + /* keep end marker to avoid strlen() */ + e = path + path_len; + + if (*path != '/') + return -FDT_ERR_BADVALUE; + + /* get fragment name first */ + s = strchr(path + 1, '/'); + if (!s) { + /* Symbol refers to something that won't end + * up in the target tree */ + continue; + } + + frag_name = path + 1; + frag_name_len = s - path - 1; + + /* verify format; safe since "s" lies in \0 terminated prop */ + len = sizeof("/__overlay__/") - 1; + if ((e - s) > len && (memcmp(s, "/__overlay__/", len) == 0)) { + /* /<fragment-name>/__overlay__/<relative-subnode-path> */ + rel_path = s + len; + rel_path_len = e - rel_path - 1; + } else if ((e - s) == len + && (memcmp(s, "/__overlay__", len - 1) == 0)) { + /* /<fragment-name>/__overlay__ */ + rel_path = ""; + rel_path_len = 0; + } else { + /* Symbol refers to something that won't end + * up in the target tree */ + continue; + } + + /* find the fragment index in which the symbol lies */ + ret = fdt_subnode_offset_namelen(fdto, 0, frag_name, + frag_name_len); + /* not found? */ + if (ret < 0) + return -FDT_ERR_BADOVERLAY; + fragment = ret; + + /* an __overlay__ subnode must exist */ + ret = fdt_subnode_offset(fdto, fragment, "__overlay__"); + if (ret < 0) + return -FDT_ERR_BADOVERLAY; + + /* get the target of the fragment */ + ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path); + if (ret < 0) + return ret; + target = ret; + + /* if we have a target path use */ + if (!target_path) { + ret = get_path_len(fdt, target); + if (ret < 0) + return ret; + len = ret; + } else { + len = strlen(target_path); + } + + ret = fdt_setprop_placeholder(fdt, root_sym, name, + len + (len > 1) + rel_path_len + 1, &p); + if (ret < 0) + return ret; + + if (!target_path) { + /* again in case setprop_placeholder changed it */ + ret = fdt_overlay_target_offset(fdt, fdto, fragment, &target_path); + if (ret < 0) + return ret; + target = ret; + } + + buf = p; + if (len > 1) { /* target is not root */ + if (!target_path) { + ret = fdt_get_path(fdt, target, buf, len + 1); + if (ret < 0) + return ret; + } else + memcpy(buf, target_path, len + 1); + + } else + len--; + + buf[len] = '/'; + memcpy(buf + len + 1, rel_path, rel_path_len); + buf[len + 1 + rel_path_len] = '\0'; + } + + return 0; +} + +int fdt_overlay_apply(void *fdt, void *fdto) +{ + uint32_t delta; + int ret; + + FDT_RO_PROBE(fdt); + FDT_RO_PROBE(fdto); + + ret = fdt_find_max_phandle(fdt, &delta); + if (ret) + goto err; + + ret = overlay_adjust_local_phandles(fdto, delta); + if (ret) + goto err; + + ret = overlay_update_local_references(fdto, delta); + if (ret) + goto err; + + ret = overlay_fixup_phandles(fdt, fdto); + if (ret) + goto err; + + ret = overlay_merge(fdt, fdto); + if (ret) + goto err; + + ret = overlay_symbol_update(fdt, fdto); + if (ret) + goto err; + + /* + * The overlay has been damaged, erase its magic. + */ + fdt_set_magic(fdto, ~0); + + return 0; + +err: + /* + * The overlay might have been damaged, erase its magic. + */ + fdt_set_magic(fdto, ~0); + + /* + * The base device tree might have been damaged, erase its + * magic. + */ + fdt_set_magic(fdt, ~0); + + return ret; +} diff --git a/lib/libfdt/fdt_ro.c b/lib/libfdt/fdt_ro.c new file mode 100644 index 0000000..9f6c551 --- /dev/null +++ b/lib/libfdt/fdt_ro.c @@ -0,0 +1,859 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +static int fdt_nodename_eq_(const void *fdt, int offset, + const char *s, int len) +{ + int olen; + const char *p = fdt_get_name(fdt, offset, &olen); + + if (!p || olen < len) + /* short match */ + return 0; + + if (memcmp(p, s, len) != 0) + return 0; + + if (p[len] == '\0') + return 1; + else if (!memchr(s, '@', len) && (p[len] == '@')) + return 1; + else + return 0; +} + +const char *fdt_get_string(const void *fdt, int stroffset, int *lenp) +{ + int32_t totalsize; + uint32_t absoffset; + size_t len; + int err; + const char *s, *n; + + if (can_assume(VALID_INPUT)) { + s = (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset; + + if (lenp) + *lenp = strlen(s); + return s; + } + totalsize = fdt_ro_probe_(fdt); + err = totalsize; + if (totalsize < 0) + goto fail; + + err = -FDT_ERR_BADOFFSET; + absoffset = stroffset + fdt_off_dt_strings(fdt); + if (absoffset >= (unsigned)totalsize) + goto fail; + len = totalsize - absoffset; + + if (fdt_magic(fdt) == FDT_MAGIC) { + if (stroffset < 0) + goto fail; + if (can_assume(LATEST) || fdt_version(fdt) >= 17) { + if ((unsigned)stroffset >= fdt_size_dt_strings(fdt)) + goto fail; + if ((fdt_size_dt_strings(fdt) - stroffset) < len) + len = fdt_size_dt_strings(fdt) - stroffset; + } + } else if (fdt_magic(fdt) == FDT_SW_MAGIC) { + unsigned int sw_stroffset = -stroffset; + + if ((stroffset >= 0) || + (sw_stroffset > fdt_size_dt_strings(fdt))) + goto fail; + if (sw_stroffset < len) + len = sw_stroffset; + } else { + err = -FDT_ERR_INTERNAL; + goto fail; + } + + s = (const char *)fdt + absoffset; + n = memchr(s, '\0', len); + if (!n) { + /* missing terminating NULL */ + err = -FDT_ERR_TRUNCATED; + goto fail; + } + + if (lenp) + *lenp = n - s; + return s; + +fail: + if (lenp) + *lenp = err; + return NULL; +} + +const char *fdt_string(const void *fdt, int stroffset) +{ + return fdt_get_string(fdt, stroffset, NULL); +} + +static int fdt_string_eq_(const void *fdt, int stroffset, + const char *s, int len) +{ + int slen; + const char *p = fdt_get_string(fdt, stroffset, &slen); + + return p && (slen == len) && (memcmp(p, s, len) == 0); +} + +int fdt_find_max_phandle(const void *fdt, uint32_t *phandle) +{ + uint32_t max = 0; + int offset = -1; + + while (true) { + uint32_t value; + + offset = fdt_next_node(fdt, offset, NULL); + if (offset < 0) { + if (offset == -FDT_ERR_NOTFOUND) + break; + + return offset; + } + + value = fdt_get_phandle(fdt, offset); + + if (value > max) + max = value; + } + + if (phandle) + *phandle = max; + + return 0; +} + +int fdt_generate_phandle(const void *fdt, uint32_t *phandle) +{ + uint32_t max; + int err; + + err = fdt_find_max_phandle(fdt, &max); + if (err < 0) + return err; + + if (max == FDT_MAX_PHANDLE) + return -FDT_ERR_NOPHANDLES; + + if (phandle) + *phandle = max + 1; + + return 0; +} + +static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n) +{ + unsigned int offset = n * sizeof(struct fdt_reserve_entry); + unsigned int absoffset = fdt_off_mem_rsvmap(fdt) + offset; + + if (!can_assume(VALID_INPUT)) { + if (absoffset < fdt_off_mem_rsvmap(fdt)) + return NULL; + if (absoffset > fdt_totalsize(fdt) - + sizeof(struct fdt_reserve_entry)) + return NULL; + } + return fdt_mem_rsv_(fdt, n); +} + +int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size) +{ + const struct fdt_reserve_entry *re; + + FDT_RO_PROBE(fdt); + re = fdt_mem_rsv(fdt, n); + if (!can_assume(VALID_INPUT) && !re) + return -FDT_ERR_BADOFFSET; + + *address = fdt64_ld_(&re->address); + *size = fdt64_ld_(&re->size); + return 0; +} + +int fdt_num_mem_rsv(const void *fdt) +{ + int i; + const struct fdt_reserve_entry *re; + + for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) { + if (fdt64_ld_(&re->size) == 0) + return i; + } + return -FDT_ERR_TRUNCATED; +} + +static int nextprop_(const void *fdt, int offset) +{ + uint32_t tag; + int nextoffset; + + do { + tag = fdt_next_tag(fdt, offset, &nextoffset); + + switch (tag) { + case FDT_END: + if (nextoffset >= 0) + return -FDT_ERR_BADSTRUCTURE; + else + return nextoffset; + + case FDT_PROP: + return offset; + } + offset = nextoffset; + } while (tag == FDT_NOP); + + return -FDT_ERR_NOTFOUND; +} + +int fdt_subnode_offset_namelen(const void *fdt, int offset, + const char *name, int namelen) +{ + int depth; + + FDT_RO_PROBE(fdt); + + for (depth = 0; + (offset >= 0) && (depth >= 0); + offset = fdt_next_node(fdt, offset, &depth)) + if ((depth == 1) + && fdt_nodename_eq_(fdt, offset, name, namelen)) + return offset; + + if (depth < 0) + return -FDT_ERR_NOTFOUND; + return offset; /* error */ +} + +int fdt_subnode_offset(const void *fdt, int parentoffset, + const char *name) +{ + return fdt_subnode_offset_namelen(fdt, parentoffset, name, strlen(name)); +} + +int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen) +{ + const char *end = path + namelen; + const char *p = path; + int offset = 0; + + FDT_RO_PROBE(fdt); + + /* see if we have an alias */ + if (*path != '/') { + const char *q = memchr(path, '/', end - p); + + if (!q) + q = end; + + p = fdt_get_alias_namelen(fdt, p, q - p); + if (!p) + return -FDT_ERR_BADPATH; + offset = fdt_path_offset(fdt, p); + + p = q; + } + + while (p < end) { + const char *q; + + while (*p == '/') { + p++; + if (p == end) + return offset; + } + q = memchr(p, '/', end - p); + if (! q) + q = end; + + offset = fdt_subnode_offset_namelen(fdt, offset, p, q-p); + if (offset < 0) + return offset; + + p = q; + } + + return offset; +} + +int fdt_path_offset(const void *fdt, const char *path) +{ + return fdt_path_offset_namelen(fdt, path, strlen(path)); +} + +const char *fdt_get_name(const void *fdt, int nodeoffset, int *len) +{ + const struct fdt_node_header *nh = fdt_offset_ptr_(fdt, nodeoffset); + const char *nameptr; + int err; + + if (((err = fdt_ro_probe_(fdt)) < 0) + || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0)) + goto fail; + + nameptr = nh->name; + + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) { + /* + * For old FDT versions, match the naming conventions of V16: + * give only the leaf name (after all /). The actual tree + * contents are loosely checked. + */ + const char *leaf; + leaf = strrchr(nameptr, '/'); + if (leaf == NULL) { + err = -FDT_ERR_BADSTRUCTURE; + goto fail; + } + nameptr = leaf+1; + } + + if (len) + *len = strlen(nameptr); + + return nameptr; + + fail: + if (len) + *len = err; + return NULL; +} + +int fdt_first_property_offset(const void *fdt, int nodeoffset) +{ + int offset; + + if ((offset = fdt_check_node_offset_(fdt, nodeoffset)) < 0) + return offset; + + return nextprop_(fdt, offset); +} + +int fdt_next_property_offset(const void *fdt, int offset) +{ + if ((offset = fdt_check_prop_offset_(fdt, offset)) < 0) + return offset; + + return nextprop_(fdt, offset); +} + +static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt, + int offset, + int *lenp) +{ + int err; + const struct fdt_property *prop; + + if (!can_assume(VALID_INPUT) && + (err = fdt_check_prop_offset_(fdt, offset)) < 0) { + if (lenp) + *lenp = err; + return NULL; + } + + prop = fdt_offset_ptr_(fdt, offset); + + if (lenp) + *lenp = fdt32_ld_(&prop->len); + + return prop; +} + +const struct fdt_property *fdt_get_property_by_offset(const void *fdt, + int offset, + int *lenp) +{ + /* Prior to version 16, properties may need realignment + * and this API does not work. fdt_getprop_*() will, however. */ + + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) { + if (lenp) + *lenp = -FDT_ERR_BADVERSION; + return NULL; + } + + return fdt_get_property_by_offset_(fdt, offset, lenp); +} + +static const struct fdt_property *fdt_get_property_namelen_(const void *fdt, + int offset, + const char *name, + int namelen, + int *lenp, + int *poffset) +{ + for (offset = fdt_first_property_offset(fdt, offset); + (offset >= 0); + (offset = fdt_next_property_offset(fdt, offset))) { + const struct fdt_property *prop; + + prop = fdt_get_property_by_offset_(fdt, offset, lenp); + if (!can_assume(LIBFDT_FLAWLESS) && !prop) { + offset = -FDT_ERR_INTERNAL; + break; + } + if (fdt_string_eq_(fdt, fdt32_ld_(&prop->nameoff), + name, namelen)) { + if (poffset) + *poffset = offset; + return prop; + } + } + + if (lenp) + *lenp = offset; + return NULL; +} + + +const struct fdt_property *fdt_get_property_namelen(const void *fdt, + int offset, + const char *name, + int namelen, int *lenp) +{ + /* Prior to version 16, properties may need realignment + * and this API does not work. fdt_getprop_*() will, however. */ + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) { + if (lenp) + *lenp = -FDT_ERR_BADVERSION; + return NULL; + } + + return fdt_get_property_namelen_(fdt, offset, name, namelen, lenp, + NULL); +} + + +const struct fdt_property *fdt_get_property(const void *fdt, + int nodeoffset, + const char *name, int *lenp) +{ + return fdt_get_property_namelen(fdt, nodeoffset, name, + strlen(name), lenp); +} + +const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, + const char *name, int namelen, int *lenp) +{ + int poffset; + const struct fdt_property *prop; + + prop = fdt_get_property_namelen_(fdt, nodeoffset, name, namelen, lenp, + &poffset); + if (!prop) + return NULL; + + /* Handle realignment */ + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 && + (poffset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8) + return prop->data + 4; + return prop->data; +} + +const void *fdt_getprop_by_offset(const void *fdt, int offset, + const char **namep, int *lenp) +{ + const struct fdt_property *prop; + + prop = fdt_get_property_by_offset_(fdt, offset, lenp); + if (!prop) + return NULL; + if (namep) { + const char *name; + int namelen; + + if (!can_assume(VALID_INPUT)) { + name = fdt_get_string(fdt, fdt32_ld_(&prop->nameoff), + &namelen); + *namep = name; + if (!name) { + if (lenp) + *lenp = namelen; + return NULL; + } + } else { + *namep = fdt_string(fdt, fdt32_ld_(&prop->nameoff)); + } + } + + /* Handle realignment */ + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 && + (offset + sizeof(*prop)) % 8 && fdt32_ld_(&prop->len) >= 8) + return prop->data + 4; + return prop->data; +} + +const void *fdt_getprop(const void *fdt, int nodeoffset, + const char *name, int *lenp) +{ + return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp); +} + +uint32_t fdt_get_phandle(const void *fdt, int nodeoffset) +{ + const fdt32_t *php; + int len; + + /* FIXME: This is a bit sub-optimal, since we potentially scan + * over all the properties twice. */ + php = fdt_getprop(fdt, nodeoffset, "phandle", &len); + if (!php || (len != sizeof(*php))) { + php = fdt_getprop(fdt, nodeoffset, "linux,phandle", &len); + if (!php || (len != sizeof(*php))) + return 0; + } + + return fdt32_ld_(php); +} + +const char *fdt_get_alias_namelen(const void *fdt, + const char *name, int namelen) +{ + int aliasoffset; + + aliasoffset = fdt_path_offset(fdt, "/aliases"); + if (aliasoffset < 0) + return NULL; + + return fdt_getprop_namelen(fdt, aliasoffset, name, namelen, NULL); +} + +const char *fdt_get_alias(const void *fdt, const char *name) +{ + return fdt_get_alias_namelen(fdt, name, strlen(name)); +} + +int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen) +{ + int pdepth = 0, p = 0; + int offset, depth, namelen; + const char *name; + + FDT_RO_PROBE(fdt); + + if (buflen < 2) + return -FDT_ERR_NOSPACE; + + for (offset = 0, depth = 0; + (offset >= 0) && (offset <= nodeoffset); + offset = fdt_next_node(fdt, offset, &depth)) { + while (pdepth > depth) { + do { + p--; + } while (buf[p-1] != '/'); + pdepth--; + } + + if (pdepth >= depth) { + name = fdt_get_name(fdt, offset, &namelen); + if (!name) + return namelen; + if ((p + namelen + 1) <= buflen) { + memcpy(buf + p, name, namelen); + p += namelen; + buf[p++] = '/'; + pdepth++; + } + } + + if (offset == nodeoffset) { + if (pdepth < (depth + 1)) + return -FDT_ERR_NOSPACE; + + if (p > 1) /* special case so that root path is "/", not "" */ + p--; + buf[p] = '\0'; + return 0; + } + } + + if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0)) + return -FDT_ERR_BADOFFSET; + else if (offset == -FDT_ERR_BADOFFSET) + return -FDT_ERR_BADSTRUCTURE; + + return offset; /* error from fdt_next_node() */ +} + +int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset, + int supernodedepth, int *nodedepth) +{ + int offset, depth; + int supernodeoffset = -FDT_ERR_INTERNAL; + + FDT_RO_PROBE(fdt); + + if (supernodedepth < 0) + return -FDT_ERR_NOTFOUND; + + for (offset = 0, depth = 0; + (offset >= 0) && (offset <= nodeoffset); + offset = fdt_next_node(fdt, offset, &depth)) { + if (depth == supernodedepth) + supernodeoffset = offset; + + if (offset == nodeoffset) { + if (nodedepth) + *nodedepth = depth; + + if (supernodedepth > depth) + return -FDT_ERR_NOTFOUND; + else + return supernodeoffset; + } + } + + if (!can_assume(VALID_INPUT)) { + if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0)) + return -FDT_ERR_BADOFFSET; + else if (offset == -FDT_ERR_BADOFFSET) + return -FDT_ERR_BADSTRUCTURE; + } + + return offset; /* error from fdt_next_node() */ +} + +int fdt_node_depth(const void *fdt, int nodeoffset) +{ + int nodedepth; + int err; + + err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth); + if (err) + return (can_assume(LIBFDT_FLAWLESS) || err < 0) ? err : + -FDT_ERR_INTERNAL; + return nodedepth; +} + +int fdt_parent_offset(const void *fdt, int nodeoffset) +{ + int nodedepth = fdt_node_depth(fdt, nodeoffset); + + if (nodedepth < 0) + return nodedepth; + return fdt_supernode_atdepth_offset(fdt, nodeoffset, + nodedepth - 1, NULL); +} + +int fdt_node_offset_by_prop_value(const void *fdt, int startoffset, + const char *propname, + const void *propval, int proplen) +{ + int offset; + const void *val; + int len; + + FDT_RO_PROBE(fdt); + + /* FIXME: The algorithm here is pretty horrible: we scan each + * property of a node in fdt_getprop(), then if that didn't + * find what we want, we scan over them again making our way + * to the next node. Still it's the easiest to implement + * approach; performance can come later. */ + for (offset = fdt_next_node(fdt, startoffset, NULL); + offset >= 0; + offset = fdt_next_node(fdt, offset, NULL)) { + val = fdt_getprop(fdt, offset, propname, &len); + if (val && (len == proplen) + && (memcmp(val, propval, len) == 0)) + return offset; + } + + return offset; /* error from fdt_next_node() */ +} + +int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle) +{ + int offset; + + if ((phandle == 0) || (phandle == ~0U)) + return -FDT_ERR_BADPHANDLE; + + FDT_RO_PROBE(fdt); + + /* FIXME: The algorithm here is pretty horrible: we + * potentially scan each property of a node in + * fdt_get_phandle(), then if that didn't find what + * we want, we scan over them again making our way to the next + * node. Still it's the easiest to implement approach; + * performance can come later. */ + for (offset = fdt_next_node(fdt, -1, NULL); + offset >= 0; + offset = fdt_next_node(fdt, offset, NULL)) { + if (fdt_get_phandle(fdt, offset) == phandle) + return offset; + } + + return offset; /* error from fdt_next_node() */ +} + +int fdt_stringlist_contains(const char *strlist, int listlen, const char *str) +{ + int len = strlen(str); + const char *p; + + while (listlen >= len) { + if (memcmp(str, strlist, len+1) == 0) + return 1; + p = memchr(strlist, '\0', listlen); + if (!p) + return 0; /* malformed strlist.. */ + listlen -= (p-strlist) + 1; + strlist = p + 1; + } + return 0; +} + +int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property) +{ + const char *list, *end; + int length, count = 0; + + list = fdt_getprop(fdt, nodeoffset, property, &length); + if (!list) + return length; + + end = list + length; + + while (list < end) { + length = strnlen(list, end - list) + 1; + + /* Abort if the last string isn't properly NUL-terminated. */ + if (list + length > end) + return -FDT_ERR_BADVALUE; + + list += length; + count++; + } + + return count; +} + +int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property, + const char *string) +{ + int length, len, idx = 0; + const char *list, *end; + + list = fdt_getprop(fdt, nodeoffset, property, &length); + if (!list) + return length; + + len = strlen(string) + 1; + end = list + length; + + while (list < end) { + length = strnlen(list, end - list) + 1; + + /* Abort if the last string isn't properly NUL-terminated. */ + if (list + length > end) + return -FDT_ERR_BADVALUE; + + if (length == len && memcmp(list, string, length) == 0) + return idx; + + list += length; + idx++; + } + + return -FDT_ERR_NOTFOUND; +} + +const char *fdt_stringlist_get(const void *fdt, int nodeoffset, + const char *property, int idx, + int *lenp) +{ + const char *list, *end; + int length; + + list = fdt_getprop(fdt, nodeoffset, property, &length); + if (!list) { + if (lenp) + *lenp = length; + + return NULL; + } + + end = list + length; + + while (list < end) { + length = strnlen(list, end - list) + 1; + + /* Abort if the last string isn't properly NUL-terminated. */ + if (list + length > end) { + if (lenp) + *lenp = -FDT_ERR_BADVALUE; + + return NULL; + } + + if (idx == 0) { + if (lenp) + *lenp = length - 1; + + return list; + } + + list += length; + idx--; + } + + if (lenp) + *lenp = -FDT_ERR_NOTFOUND; + + return NULL; +} + +int fdt_node_check_compatible(const void *fdt, int nodeoffset, + const char *compatible) +{ + const void *prop; + int len; + + prop = fdt_getprop(fdt, nodeoffset, "compatible", &len); + if (!prop) + return len; + + return !fdt_stringlist_contains(prop, len, compatible); +} + +int fdt_node_offset_by_compatible(const void *fdt, int startoffset, + const char *compatible) +{ + int offset, err; + + FDT_RO_PROBE(fdt); + + /* FIXME: The algorithm here is pretty horrible: we scan each + * property of a node in fdt_node_check_compatible(), then if + * that didn't find what we want, we scan over them again + * making our way to the next node. Still it's the easiest to + * implement approach; performance can come later. */ + for (offset = fdt_next_node(fdt, startoffset, NULL); + offset >= 0; + offset = fdt_next_node(fdt, offset, NULL)) { + err = fdt_node_check_compatible(fdt, offset, compatible); + if ((err < 0) && (err != -FDT_ERR_NOTFOUND)) + return err; + else if (err == 0) + return offset; + } + + return offset; /* error from fdt_next_node() */ +} diff --git a/lib/libfdt/fdt_rw.c b/lib/libfdt/fdt_rw.c new file mode 100644 index 0000000..3621d36 --- /dev/null +++ b/lib/libfdt/fdt_rw.c @@ -0,0 +1,500 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +static int fdt_blocks_misordered_(const void *fdt, + int mem_rsv_size, int struct_size) +{ + return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8)) + || (fdt_off_dt_struct(fdt) < + (fdt_off_mem_rsvmap(fdt) + mem_rsv_size)) + || (fdt_off_dt_strings(fdt) < + (fdt_off_dt_struct(fdt) + struct_size)) + || (fdt_totalsize(fdt) < + (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt))); +} + +static int fdt_rw_probe_(void *fdt) +{ + if (can_assume(VALID_DTB)) + return 0; + FDT_RO_PROBE(fdt); + + if (!can_assume(LATEST) && fdt_version(fdt) < 17) + return -FDT_ERR_BADVERSION; + if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry), + fdt_size_dt_struct(fdt))) + return -FDT_ERR_BADLAYOUT; + if (!can_assume(LATEST) && fdt_version(fdt) > 17) + fdt_set_version(fdt, 17); + + return 0; +} + +#define FDT_RW_PROBE(fdt) \ + { \ + int err_; \ + if ((err_ = fdt_rw_probe_(fdt)) != 0) \ + return err_; \ + } + +static inline unsigned int fdt_data_size_(void *fdt) +{ + return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); +} + +static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen) +{ + char *p = splicepoint; + unsigned int dsize = fdt_data_size_(fdt); + size_t soff = p - (char *)fdt; + + if ((oldlen < 0) || (soff + oldlen < soff) || (soff + oldlen > dsize)) + return -FDT_ERR_BADOFFSET; + if ((p < (char *)fdt) || (dsize + newlen < (unsigned)oldlen)) + return -FDT_ERR_BADOFFSET; + if (dsize - oldlen + newlen > fdt_totalsize(fdt)) + return -FDT_ERR_NOSPACE; + memmove(p + newlen, p + oldlen, ((char *)fdt + dsize) - (p + oldlen)); + return 0; +} + +static int fdt_splice_mem_rsv_(void *fdt, struct fdt_reserve_entry *p, + int oldn, int newn) +{ + int delta = (newn - oldn) * sizeof(*p); + int err; + err = fdt_splice_(fdt, p, oldn * sizeof(*p), newn * sizeof(*p)); + if (err) + return err; + fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta); + fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta); + return 0; +} + +static int fdt_splice_struct_(void *fdt, void *p, + int oldlen, int newlen) +{ + int delta = newlen - oldlen; + int err; + + if ((err = fdt_splice_(fdt, p, oldlen, newlen))) + return err; + + fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta); + fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta); + return 0; +} + +/* Must only be used to roll back in case of error */ +static void fdt_del_last_string_(void *fdt, const char *s) +{ + int newlen = strlen(s) + 1; + + fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) - newlen); +} + +static int fdt_splice_string_(void *fdt, int newlen) +{ + void *p = (char *)fdt + + fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); + int err; + + if ((err = fdt_splice_(fdt, p, 0, newlen))) + return err; + + fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen); + return 0; +} + +/** + * fdt_find_add_string_() - Find or allocate a string + * + * @fdt: pointer to the device tree to check/adjust + * @s: string to find/add + * @allocated: Set to 0 if the string was found, 1 if not found and so + * allocated. Ignored if can_assume(NO_ROLLBACK) + * @return offset of string in the string table (whether found or added) + */ +static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) +{ + char *strtab = (char *)fdt + fdt_off_dt_strings(fdt); + const char *p; + char *new; + int len = strlen(s) + 1; + int err; + + if (!can_assume(NO_ROLLBACK)) + *allocated = 0; + + p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s); + if (p) + /* found it */ + return (p - strtab); + + new = strtab + fdt_size_dt_strings(fdt); + err = fdt_splice_string_(fdt, len); + if (err) + return err; + + if (!can_assume(NO_ROLLBACK)) + *allocated = 1; + + memcpy(new, s, len); + return (new - strtab); +} + +int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size) +{ + struct fdt_reserve_entry *re; + int err; + + FDT_RW_PROBE(fdt); + + re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt)); + err = fdt_splice_mem_rsv_(fdt, re, 0, 1); + if (err) + return err; + + re->address = cpu_to_fdt64(address); + re->size = cpu_to_fdt64(size); + return 0; +} + +int fdt_del_mem_rsv(void *fdt, int n) +{ + struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n); + + FDT_RW_PROBE(fdt); + + if (n >= fdt_num_mem_rsv(fdt)) + return -FDT_ERR_NOTFOUND; + + return fdt_splice_mem_rsv_(fdt, re, 1, 0); +} + +static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name, + int len, struct fdt_property **prop) +{ + int oldlen; + int err; + + *prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen); + if (!*prop) + return oldlen; + + if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen), + FDT_TAGALIGN(len)))) + return err; + + (*prop)->len = cpu_to_fdt32(len); + return 0; +} + +static int fdt_add_property_(void *fdt, int nodeoffset, const char *name, + int len, struct fdt_property **prop) +{ + int proplen; + int nextoffset; + int namestroff; + int err; + int allocated; + + if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0) + return nextoffset; + + namestroff = fdt_find_add_string_(fdt, name, &allocated); + if (namestroff < 0) + return namestroff; + + *prop = fdt_offset_ptr_w_(fdt, nextoffset); + proplen = sizeof(**prop) + FDT_TAGALIGN(len); + + err = fdt_splice_struct_(fdt, *prop, 0, proplen); + if (err) { + /* Delete the string if we failed to add it */ + if (!can_assume(NO_ROLLBACK) && allocated) + fdt_del_last_string_(fdt, name); + return err; + } + + (*prop)->tag = cpu_to_fdt32(FDT_PROP); + (*prop)->nameoff = cpu_to_fdt32(namestroff); + (*prop)->len = cpu_to_fdt32(len); + return 0; +} + +int fdt_set_name(void *fdt, int nodeoffset, const char *name) +{ + char *namep; + int oldlen, newlen; + int err; + + FDT_RW_PROBE(fdt); + + namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen); + if (!namep) + return oldlen; + + newlen = strlen(name); + + err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1), + FDT_TAGALIGN(newlen+1)); + if (err) + return err; + + memcpy(namep, name, newlen+1); + return 0; +} + +int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name, + int len, void **prop_data) +{ + struct fdt_property *prop; + int err; + + FDT_RW_PROBE(fdt); + + err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop); + if (err == -FDT_ERR_NOTFOUND) + err = fdt_add_property_(fdt, nodeoffset, name, len, &prop); + if (err) + return err; + + *prop_data = prop->data; + return 0; +} + +int fdt_setprop(void *fdt, int nodeoffset, const char *name, + const void *val, int len) +{ + void *prop_data; + int err; + + err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data); + if (err) + return err; + + if (len) + memcpy(prop_data, val, len); + return 0; +} + +int fdt_appendprop(void *fdt, int nodeoffset, const char *name, + const void *val, int len) +{ + struct fdt_property *prop; + int err, oldlen, newlen; + + FDT_RW_PROBE(fdt); + + prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen); + if (prop) { + newlen = len + oldlen; + err = fdt_splice_struct_(fdt, prop->data, + FDT_TAGALIGN(oldlen), + FDT_TAGALIGN(newlen)); + if (err) + return err; + prop->len = cpu_to_fdt32(newlen); + memcpy(prop->data + oldlen, val, len); + } else { + err = fdt_add_property_(fdt, nodeoffset, name, len, &prop); + if (err) + return err; + memcpy(prop->data, val, len); + } + return 0; +} + +int fdt_delprop(void *fdt, int nodeoffset, const char *name) +{ + struct fdt_property *prop; + int len, proplen; + + FDT_RW_PROBE(fdt); + + prop = fdt_get_property_w(fdt, nodeoffset, name, &len); + if (!prop) + return len; + + proplen = sizeof(*prop) + FDT_TAGALIGN(len); + return fdt_splice_struct_(fdt, prop, proplen, 0); +} + +int fdt_add_subnode_namelen(void *fdt, int parentoffset, + const char *name, int namelen) +{ + struct fdt_node_header *nh; + int offset, nextoffset; + int nodelen; + int err; + uint32_t tag; + fdt32_t *endtag; + + FDT_RW_PROBE(fdt); + + offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen); + if (offset >= 0) + return -FDT_ERR_EXISTS; + else if (offset != -FDT_ERR_NOTFOUND) + return offset; + + /* Try to place the new node after the parent's properties */ + tag = fdt_next_tag(fdt, parentoffset, &nextoffset); + /* the fdt_subnode_offset_namelen() should ensure this never hits */ + if (!can_assume(LIBFDT_FLAWLESS) && (tag != FDT_BEGIN_NODE)) + return -FDT_ERR_INTERNAL; + do { + offset = nextoffset; + tag = fdt_next_tag(fdt, offset, &nextoffset); + } while ((tag == FDT_PROP) || (tag == FDT_NOP)); + + nh = fdt_offset_ptr_w_(fdt, offset); + nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE; + + err = fdt_splice_struct_(fdt, nh, 0, nodelen); + if (err) + return err; + + nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); + memset(nh->name, 0, FDT_TAGALIGN(namelen+1)); + memcpy(nh->name, name, namelen); + endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE); + *endtag = cpu_to_fdt32(FDT_END_NODE); + + return offset; +} + +int fdt_add_subnode(void *fdt, int parentoffset, const char *name) +{ + return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name)); +} + +int fdt_del_node(void *fdt, int nodeoffset) +{ + int endoffset; + + FDT_RW_PROBE(fdt); + + endoffset = fdt_node_end_offset_(fdt, nodeoffset); + if (endoffset < 0) + return endoffset; + + return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset), + endoffset - nodeoffset, 0); +} + +static void fdt_packblocks_(const char *old, char *new, + int mem_rsv_size, + int struct_size, + int strings_size) +{ + int mem_rsv_off, struct_off, strings_off; + + mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8); + struct_off = mem_rsv_off + mem_rsv_size; + strings_off = struct_off + struct_size; + + memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size); + fdt_set_off_mem_rsvmap(new, mem_rsv_off); + + memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size); + fdt_set_off_dt_struct(new, struct_off); + fdt_set_size_dt_struct(new, struct_size); + + memmove(new + strings_off, old + fdt_off_dt_strings(old), strings_size); + fdt_set_off_dt_strings(new, strings_off); + fdt_set_size_dt_strings(new, fdt_size_dt_strings(old)); +} + +int fdt_open_into(const void *fdt, void *buf, int bufsize) +{ + int err; + int mem_rsv_size, struct_size; + int newsize; + const char *fdtstart = fdt; + const char *fdtend = fdtstart + fdt_totalsize(fdt); + char *tmp; + + FDT_RO_PROBE(fdt); + + mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) + * sizeof(struct fdt_reserve_entry); + + if (can_assume(LATEST) || fdt_version(fdt) >= 17) { + struct_size = fdt_size_dt_struct(fdt); + } else if (fdt_version(fdt) == 16) { + struct_size = 0; + while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END) + ; + if (struct_size < 0) + return struct_size; + } else { + return -FDT_ERR_BADVERSION; + } + + if (can_assume(LIBFDT_ORDER) || + !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) { + /* no further work necessary */ + err = fdt_move(fdt, buf, bufsize); + if (err) + return err; + fdt_set_version(buf, 17); + fdt_set_size_dt_struct(buf, struct_size); + fdt_set_totalsize(buf, bufsize); + return 0; + } + + /* Need to reorder */ + newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size + + struct_size + fdt_size_dt_strings(fdt); + + if (bufsize < newsize) + return -FDT_ERR_NOSPACE; + + /* First attempt to build converted tree at beginning of buffer */ + tmp = buf; + /* But if that overlaps with the old tree... */ + if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) { + /* Try right after the old tree instead */ + tmp = (char *)(uintptr_t)fdtend; + if ((tmp + newsize) > ((char *)buf + bufsize)) + return -FDT_ERR_NOSPACE; + } + + fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size, + fdt_size_dt_strings(fdt)); + memmove(buf, tmp, newsize); + + fdt_set_magic(buf, FDT_MAGIC); + fdt_set_totalsize(buf, bufsize); + fdt_set_version(buf, 17); + fdt_set_last_comp_version(buf, 16); + fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt)); + + return 0; +} + +int fdt_pack(void *fdt) +{ + int mem_rsv_size; + + FDT_RW_PROBE(fdt); + + mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) + * sizeof(struct fdt_reserve_entry); + fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt), + fdt_size_dt_strings(fdt)); + fdt_set_totalsize(fdt, fdt_data_size_(fdt)); + + return 0; +} diff --git a/lib/libfdt/fdt_strerror.c b/lib/libfdt/fdt_strerror.c new file mode 100644 index 0000000..d852b77 --- /dev/null +++ b/lib/libfdt/fdt_strerror.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +struct fdt_errtabent { + const char *str; +}; + +#define FDT_ERRTABENT(val) \ + [(val)] = { .str = #val, } + +static struct fdt_errtabent fdt_errtable[] = { + FDT_ERRTABENT(FDT_ERR_NOTFOUND), + FDT_ERRTABENT(FDT_ERR_EXISTS), + FDT_ERRTABENT(FDT_ERR_NOSPACE), + + FDT_ERRTABENT(FDT_ERR_BADOFFSET), + FDT_ERRTABENT(FDT_ERR_BADPATH), + FDT_ERRTABENT(FDT_ERR_BADPHANDLE), + FDT_ERRTABENT(FDT_ERR_BADSTATE), + + FDT_ERRTABENT(FDT_ERR_TRUNCATED), + FDT_ERRTABENT(FDT_ERR_BADMAGIC), + FDT_ERRTABENT(FDT_ERR_BADVERSION), + FDT_ERRTABENT(FDT_ERR_BADSTRUCTURE), + FDT_ERRTABENT(FDT_ERR_BADLAYOUT), + FDT_ERRTABENT(FDT_ERR_INTERNAL), + FDT_ERRTABENT(FDT_ERR_BADNCELLS), + FDT_ERRTABENT(FDT_ERR_BADVALUE), + FDT_ERRTABENT(FDT_ERR_BADOVERLAY), + FDT_ERRTABENT(FDT_ERR_NOPHANDLES), + FDT_ERRTABENT(FDT_ERR_BADFLAGS), + FDT_ERRTABENT(FDT_ERR_ALIGNMENT), +}; +#define FDT_ERRTABSIZE ((int)(sizeof(fdt_errtable) / sizeof(fdt_errtable[0]))) + +const char *fdt_strerror(int errval) +{ + if (errval > 0) + return "<valid offset/length>"; + else if (errval == 0) + return "<no error>"; + else if (-errval < FDT_ERRTABSIZE) { + const char *s = fdt_errtable[-errval].str; + + if (s) + return s; + } + + return "<unknown error>"; +} diff --git a/lib/libfdt/fdt_sw.c b/lib/libfdt/fdt_sw.c new file mode 100644 index 0000000..4c569ee --- /dev/null +++ b/lib/libfdt/fdt_sw.c @@ -0,0 +1,384 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +static int fdt_sw_probe_(void *fdt) +{ + if (!can_assume(VALID_INPUT)) { + if (fdt_magic(fdt) == FDT_MAGIC) + return -FDT_ERR_BADSTATE; + else if (fdt_magic(fdt) != FDT_SW_MAGIC) + return -FDT_ERR_BADMAGIC; + } + + return 0; +} + +#define FDT_SW_PROBE(fdt) \ + { \ + int err; \ + if ((err = fdt_sw_probe_(fdt)) != 0) \ + return err; \ + } + +/* 'memrsv' state: Initial state after fdt_create() + * + * Allowed functions: + * fdt_add_reservemap_entry() + * fdt_finish_reservemap() [moves to 'struct' state] + */ +static int fdt_sw_probe_memrsv_(void *fdt) +{ + int err = fdt_sw_probe_(fdt); + if (err) + return err; + + if (!can_assume(VALID_INPUT) && fdt_off_dt_strings(fdt) != 0) + return -FDT_ERR_BADSTATE; + return 0; +} + +#define FDT_SW_PROBE_MEMRSV(fdt) \ + { \ + int err; \ + if ((err = fdt_sw_probe_memrsv_(fdt)) != 0) \ + return err; \ + } + +/* 'struct' state: Enter this state after fdt_finish_reservemap() + * + * Allowed functions: + * fdt_begin_node() + * fdt_end_node() + * fdt_property*() + * fdt_finish() [moves to 'complete' state] + */ +static int fdt_sw_probe_struct_(void *fdt) +{ + int err = fdt_sw_probe_(fdt); + if (err) + return err; + + if (!can_assume(VALID_INPUT) && + fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) + return -FDT_ERR_BADSTATE; + return 0; +} + +#define FDT_SW_PROBE_STRUCT(fdt) \ + { \ + int err; \ + if ((err = fdt_sw_probe_struct_(fdt)) != 0) \ + return err; \ + } + +static inline uint32_t sw_flags(void *fdt) +{ + /* assert: (fdt_magic(fdt) == FDT_SW_MAGIC) */ + return fdt_last_comp_version(fdt); +} + +/* 'complete' state: Enter this state after fdt_finish() + * + * Allowed functions: none + */ + +static void *fdt_grab_space_(void *fdt, size_t len) +{ + unsigned int offset = fdt_size_dt_struct(fdt); + unsigned int spaceleft; + + spaceleft = fdt_totalsize(fdt) - fdt_off_dt_struct(fdt) + - fdt_size_dt_strings(fdt); + + if ((offset + len < offset) || (offset + len > spaceleft)) + return NULL; + + fdt_set_size_dt_struct(fdt, offset + len); + return fdt_offset_ptr_w_(fdt, offset); +} + +int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags) +{ + const int hdrsize = FDT_ALIGN(sizeof(struct fdt_header), + sizeof(struct fdt_reserve_entry)); + void *fdt = buf; + + if (bufsize < hdrsize) + return -FDT_ERR_NOSPACE; + + if (flags & ~FDT_CREATE_FLAGS_ALL) + return -FDT_ERR_BADFLAGS; + + memset(buf, 0, bufsize); + + /* + * magic and last_comp_version keep intermediate state during the fdt + * creation process, which is replaced with the proper FDT format by + * fdt_finish(). + * + * flags should be accessed with sw_flags(). + */ + fdt_set_magic(fdt, FDT_SW_MAGIC); + fdt_set_version(fdt, FDT_LAST_SUPPORTED_VERSION); + fdt_set_last_comp_version(fdt, flags); + + fdt_set_totalsize(fdt, bufsize); + + fdt_set_off_mem_rsvmap(fdt, hdrsize); + fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt)); + fdt_set_off_dt_strings(fdt, 0); + + return 0; +} + +int fdt_create(void *buf, int bufsize) +{ + return fdt_create_with_flags(buf, bufsize, 0); +} + +int fdt_resize(void *fdt, void *buf, int bufsize) +{ + size_t headsize, tailsize; + char *oldtail, *newtail; + + FDT_SW_PROBE(fdt); + + if (bufsize < 0) + return -FDT_ERR_NOSPACE; + + headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); + tailsize = fdt_size_dt_strings(fdt); + + if (!can_assume(VALID_DTB) && + headsize + tailsize > fdt_totalsize(fdt)) + return -FDT_ERR_INTERNAL; + + if ((headsize + tailsize) > (unsigned)bufsize) + return -FDT_ERR_NOSPACE; + + oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize; + newtail = (char *)buf + bufsize - tailsize; + + /* Two cases to avoid clobbering data if the old and new + * buffers partially overlap */ + if (buf <= fdt) { + memmove(buf, fdt, headsize); + memmove(newtail, oldtail, tailsize); + } else { + memmove(newtail, oldtail, tailsize); + memmove(buf, fdt, headsize); + } + + fdt_set_totalsize(buf, bufsize); + if (fdt_off_dt_strings(buf)) + fdt_set_off_dt_strings(buf, bufsize); + + return 0; +} + +int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size) +{ + struct fdt_reserve_entry *re; + int offset; + + FDT_SW_PROBE_MEMRSV(fdt); + + offset = fdt_off_dt_struct(fdt); + if ((offset + sizeof(*re)) > fdt_totalsize(fdt)) + return -FDT_ERR_NOSPACE; + + re = (struct fdt_reserve_entry *)((char *)fdt + offset); + re->address = cpu_to_fdt64(addr); + re->size = cpu_to_fdt64(size); + + fdt_set_off_dt_struct(fdt, offset + sizeof(*re)); + + return 0; +} + +int fdt_finish_reservemap(void *fdt) +{ + int err = fdt_add_reservemap_entry(fdt, 0, 0); + + if (err) + return err; + + fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt)); + return 0; +} + +int fdt_begin_node(void *fdt, const char *name) +{ + struct fdt_node_header *nh; + int namelen; + + FDT_SW_PROBE_STRUCT(fdt); + + namelen = strlen(name) + 1; + nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen)); + if (! nh) + return -FDT_ERR_NOSPACE; + + nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE); + memcpy(nh->name, name, namelen); + return 0; +} + +int fdt_end_node(void *fdt) +{ + fdt32_t *en; + + FDT_SW_PROBE_STRUCT(fdt); + + en = fdt_grab_space_(fdt, FDT_TAGSIZE); + if (! en) + return -FDT_ERR_NOSPACE; + + *en = cpu_to_fdt32(FDT_END_NODE); + return 0; +} + +static int fdt_add_string_(void *fdt, const char *s) +{ + char *strtab = (char *)fdt + fdt_totalsize(fdt); + unsigned int strtabsize = fdt_size_dt_strings(fdt); + unsigned int len = strlen(s) + 1; + unsigned int struct_top, offset; + + offset = strtabsize + len; + struct_top = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); + if (fdt_totalsize(fdt) - offset < struct_top) + return 0; /* no more room :( */ + + memcpy(strtab - offset, s, len); + fdt_set_size_dt_strings(fdt, strtabsize + len); + return -offset; +} + +/* Must only be used to roll back in case of error */ +static void fdt_del_last_string_(void *fdt, const char *s) +{ + int strtabsize = fdt_size_dt_strings(fdt); + int len = strlen(s) + 1; + + fdt_set_size_dt_strings(fdt, strtabsize - len); +} + +static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) +{ + char *strtab = (char *)fdt + fdt_totalsize(fdt); + int strtabsize = fdt_size_dt_strings(fdt); + const char *p; + + *allocated = 0; + + p = fdt_find_string_(strtab - strtabsize, strtabsize, s); + if (p) + return p - strtab; + + *allocated = 1; + + return fdt_add_string_(fdt, s); +} + +int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp) +{ + struct fdt_property *prop; + int nameoff; + int allocated; + + FDT_SW_PROBE_STRUCT(fdt); + + /* String de-duplication can be slow, _NO_NAME_DEDUP skips it */ + if (sw_flags(fdt) & FDT_CREATE_FLAG_NO_NAME_DEDUP) { + allocated = 1; + nameoff = fdt_add_string_(fdt, name); + } else { + nameoff = fdt_find_add_string_(fdt, name, &allocated); + } + if (nameoff == 0) + return -FDT_ERR_NOSPACE; + + prop = fdt_grab_space_(fdt, sizeof(*prop) + FDT_TAGALIGN(len)); + if (! prop) { + if (allocated) + fdt_del_last_string_(fdt, name); + return -FDT_ERR_NOSPACE; + } + + prop->tag = cpu_to_fdt32(FDT_PROP); + prop->nameoff = cpu_to_fdt32(nameoff); + prop->len = cpu_to_fdt32(len); + *valp = prop->data; + return 0; +} + +int fdt_property(void *fdt, const char *name, const void *val, int len) +{ + void *ptr; + int ret; + + ret = fdt_property_placeholder(fdt, name, len, &ptr); + if (ret) + return ret; + memcpy(ptr, val, len); + return 0; +} + +int fdt_finish(void *fdt) +{ + char *p = (char *)fdt; + fdt32_t *end; + int oldstroffset, newstroffset; + uint32_t tag; + int offset, nextoffset; + + FDT_SW_PROBE_STRUCT(fdt); + + /* Add terminator */ + end = fdt_grab_space_(fdt, sizeof(*end)); + if (! end) + return -FDT_ERR_NOSPACE; + *end = cpu_to_fdt32(FDT_END); + + /* Relocate the string table */ + oldstroffset = fdt_totalsize(fdt) - fdt_size_dt_strings(fdt); + newstroffset = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); + memmove(p + newstroffset, p + oldstroffset, fdt_size_dt_strings(fdt)); + fdt_set_off_dt_strings(fdt, newstroffset); + + /* Walk the structure, correcting string offsets */ + offset = 0; + while ((tag = fdt_next_tag(fdt, offset, &nextoffset)) != FDT_END) { + if (tag == FDT_PROP) { + struct fdt_property *prop = + fdt_offset_ptr_w_(fdt, offset); + int nameoff; + + nameoff = fdt32_to_cpu(prop->nameoff); + nameoff += fdt_size_dt_strings(fdt); + prop->nameoff = cpu_to_fdt32(nameoff); + } + offset = nextoffset; + } + if (nextoffset < 0) + return nextoffset; + + /* Finally, adjust the header */ + fdt_set_totalsize(fdt, newstroffset + fdt_size_dt_strings(fdt)); + + /* And fix up fields that were keeping intermediate state. */ + fdt_set_last_comp_version(fdt, FDT_LAST_COMPATIBLE_VERSION); + fdt_set_magic(fdt, FDT_MAGIC); + + return 0; +} diff --git a/lib/libfdt/fdt_wip.c b/lib/libfdt/fdt_wip.c new file mode 100644 index 0000000..c2d7566 --- /dev/null +++ b/lib/libfdt/fdt_wip.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + */ +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset, + const char *name, int namelen, + uint32_t idx, const void *val, + int len) +{ + void *propval; + int proplen; + + propval = fdt_getprop_namelen_w(fdt, nodeoffset, name, namelen, + &proplen); + if (!propval) + return proplen; + + if ((unsigned)proplen < (len + idx)) + return -FDT_ERR_NOSPACE; + + memcpy((char *)propval + idx, val, len); + return 0; +} + +int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name, + const void *val, int len) +{ + const void *propval; + int proplen; + + propval = fdt_getprop(fdt, nodeoffset, name, &proplen); + if (!propval) + return proplen; + + if (proplen != len) + return -FDT_ERR_NOSPACE; + + return fdt_setprop_inplace_namelen_partial(fdt, nodeoffset, name, + strlen(name), 0, + val, len); +} + +static void fdt_nop_region_(void *start, int len) +{ + fdt32_t *p; + + for (p = start; (char *)p < ((char *)start + len); p++) + *p = cpu_to_fdt32(FDT_NOP); +} + +int fdt_nop_property(void *fdt, int nodeoffset, const char *name) +{ + struct fdt_property *prop; + int len; + + prop = fdt_get_property_w(fdt, nodeoffset, name, &len); + if (!prop) + return len; + + fdt_nop_region_(prop, len + sizeof(*prop)); + + return 0; +} + +int fdt_node_end_offset_(void *fdt, int offset) +{ + int depth = 0; + + while ((offset >= 0) && (depth >= 0)) + offset = fdt_next_node(fdt, offset, &depth); + + return offset; +} + +int fdt_nop_node(void *fdt, int nodeoffset) +{ + int endoffset; + + endoffset = fdt_node_end_offset_(fdt, nodeoffset); + if (endoffset < 0) + return endoffset; + + fdt_nop_region_(fdt_offset_ptr_w(fdt, nodeoffset, 0), + endoffset - nodeoffset); + return 0; +} diff --git a/lib/libfdt/libfdt.mk b/lib/libfdt/libfdt.mk new file mode 100644 index 0000000..1cbbd78 --- /dev/null +++ b/lib/libfdt/libfdt.mk @@ -0,0 +1,19 @@ +# +# Copyright (c) 2016, ARM Limited and Contributors. All rights reserved. +# +# SPDX-License-Identifier: BSD-3-Clause +# + +LIBFDT_SRCS := $(addprefix lib/libfdt/, \ + fdt.c \ + fdt_addresses.c \ + fdt_empty_tree.c \ + fdt_ro.c \ + fdt_rw.c \ + fdt_strerror.c \ + fdt_sw.c \ + fdt_wip.c) \ + +INCLUDES += -Iinclude/lib/libfdt + +$(eval $(call MAKE_LIB,fdt)) diff --git a/lib/libfdt/libfdt_internal.h b/lib/libfdt/libfdt_internal.h new file mode 100644 index 0000000..16bda19 --- /dev/null +++ b/lib/libfdt/libfdt_internal.h @@ -0,0 +1,192 @@ +/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */ +#ifndef LIBFDT_INTERNAL_H +#define LIBFDT_INTERNAL_H +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2006 David Gibson, IBM Corporation. + */ +#include <fdt.h> + +#define FDT_ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1)) +#define FDT_TAGALIGN(x) (FDT_ALIGN((x), FDT_TAGSIZE)) + +int32_t fdt_ro_probe_(const void *fdt); +#define FDT_RO_PROBE(fdt) \ + { \ + int32_t totalsize_; \ + if ((totalsize_ = fdt_ro_probe_(fdt)) < 0) \ + return totalsize_; \ + } + +int fdt_check_node_offset_(const void *fdt, int offset); +int fdt_check_prop_offset_(const void *fdt, int offset); +const char *fdt_find_string_(const char *strtab, int tabsize, const char *s); +int fdt_node_end_offset_(void *fdt, int nodeoffset); + +static inline const void *fdt_offset_ptr_(const void *fdt, int offset) +{ + return (const char *)fdt + fdt_off_dt_struct(fdt) + offset; +} + +static inline void *fdt_offset_ptr_w_(void *fdt, int offset) +{ + return (void *)(uintptr_t)fdt_offset_ptr_(fdt, offset); +} + +static inline const struct fdt_reserve_entry *fdt_mem_rsv_(const void *fdt, int n) +{ + const struct fdt_reserve_entry *rsv_table = + (const struct fdt_reserve_entry *) + ((const char *)fdt + fdt_off_mem_rsvmap(fdt)); + + return rsv_table + n; +} +static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n) +{ + return (void *)(uintptr_t)fdt_mem_rsv_(fdt, n); +} + +/* + * Internal helpers to access tructural elements of the device tree + * blob (rather than for exaple reading integers from within property + * values). We assume that we are either given a naturally aligned + * address for the platform or if we are not, we are on a platform + * where unaligned memory reads will be handled in a graceful manner. + * If not the external helpers fdtXX_ld() from libfdt.h can be used + * instead. + */ +static inline uint32_t fdt32_ld_(const fdt32_t *p) +{ + return fdt32_to_cpu(*p); +} + +static inline uint64_t fdt64_ld_(const fdt64_t *p) +{ + return fdt64_to_cpu(*p); +} + +#define FDT_SW_MAGIC (~FDT_MAGIC) + +/**********************************************************************/ +/* Checking controls */ +/**********************************************************************/ + +#ifndef FDT_ASSUME_MASK +#define FDT_ASSUME_MASK 0 +#endif + +/* + * Defines assumptions which can be enabled. Each of these can be enabled + * individually. For maximum safety, don't enable any assumptions! + * + * For minimal code size and no safety, use ASSUME_PERFECT at your own risk. + * You should have another method of validating the device tree, such as a + * signature or hash check before using libfdt. + * + * For situations where security is not a concern it may be safe to enable + * ASSUME_SANE. + */ +enum { + /* + * This does essentially no checks. Only the latest device-tree + * version is correctly handled. Inconsistencies or errors in the device + * tree may cause undefined behaviour or crashes. Invalid parameters + * passed to libfdt may do the same. + * + * If an error occurs when modifying the tree it may leave the tree in + * an intermediate (but valid) state. As an example, adding a property + * where there is insufficient space may result in the property name + * being added to the string table even though the property itself is + * not added to the struct section. + * + * Only use this if you have a fully validated device tree with + * the latest supported version and wish to minimise code size. + */ + ASSUME_PERFECT = 0xff, + + /* + * This assumes that the device tree is sane. i.e. header metadata + * and basic hierarchy are correct. + * + * With this assumption enabled, normal device trees produced by libfdt + * and the compiler should be handled safely. Malicious device trees and + * complete garbage may cause libfdt to behave badly or crash. Truncated + * device trees (e.g. those only partially loaded) can also cause + * problems. + * + * Note: Only checks that relate exclusively to the device tree itself + * (not the parameters passed to libfdt) are disabled by this + * assumption. This includes checking headers, tags and the like. + */ + ASSUME_VALID_DTB = 1 << 0, + + /* + * This builds on ASSUME_VALID_DTB and further assumes that libfdt + * functions are called with valid parameters, i.e. not trigger + * FDT_ERR_BADOFFSET or offsets that are out of bounds. It disables any + * extensive checking of parameters and the device tree, making various + * assumptions about correctness. + * + * It doesn't make sense to enable this assumption unless + * ASSUME_VALID_DTB is also enabled. + */ + ASSUME_VALID_INPUT = 1 << 1, + + /* + * This disables checks for device-tree version and removes all code + * which handles older versions. + * + * Only enable this if you know you have a device tree with the latest + * version. + */ + ASSUME_LATEST = 1 << 2, + + /* + * This assumes that it is OK for a failed addition to the device tree, + * due to lack of space or some other problem, to skip any rollback + * steps (such as dropping the property name from the string table). + * This is safe to enable in most circumstances, even though it may + * leave the tree in a sub-optimal state. + */ + ASSUME_NO_ROLLBACK = 1 << 3, + + /* + * This assumes that the device tree components appear in a 'convenient' + * order, i.e. the memory reservation block first, then the structure + * block and finally the string block. + * + * This order is not specified by the device-tree specification, + * but is expected by libfdt. The device-tree compiler always created + * device trees with this order. + * + * This assumption disables a check in fdt_open_into() and removes the + * ability to fix the problem there. This is safe if you know that the + * device tree is correctly ordered. See fdt_blocks_misordered_(). + */ + ASSUME_LIBFDT_ORDER = 1 << 4, + + /* + * This assumes that libfdt itself does not have any internal bugs. It + * drops certain checks that should never be needed unless libfdt has an + * undiscovered bug. + * + * This can generally be considered safe to enable. + */ + ASSUME_LIBFDT_FLAWLESS = 1 << 5, +}; + +/** + * can_assume_() - check if a particular assumption is enabled + * + * @mask: Mask to check (ASSUME_...) + * @return true if that assumption is enabled, else false + */ +static inline bool can_assume_(int mask) +{ + return FDT_ASSUME_MASK & mask; +} + +/** helper macros for checking assumptions */ +#define can_assume(_assume) can_assume_(ASSUME_ ## _assume) + +#endif /* LIBFDT_INTERNAL_H */ |