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path: root/drivers/firmware/efi/libstub/fdt.c
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Diffstat (limited to 'drivers/firmware/efi/libstub/fdt.c')
-rw-r--r--drivers/firmware/efi/libstub/fdt.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
new file mode 100644
index 000000000..70e9789ff
--- /dev/null
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FDT related Helper functions used by the EFI stub on multiple
+ * architectures. This should be #included by the EFI stub
+ * implementation files.
+ *
+ * Copyright 2013 Linaro Limited; author Roy Franz
+ */
+
+#include <linux/efi.h>
+#include <linux/libfdt.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+#define EFI_DT_ADDR_CELLS_DEFAULT 2
+#define EFI_DT_SIZE_CELLS_DEFAULT 2
+
+static void fdt_update_cell_size(void *fdt)
+{
+ int offset;
+
+ offset = fdt_path_offset(fdt, "/");
+ /* Set the #address-cells and #size-cells values for an empty tree */
+
+ fdt_setprop_u32(fdt, offset, "#address-cells", EFI_DT_ADDR_CELLS_DEFAULT);
+ fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT);
+}
+
+static efi_status_t update_fdt(void *orig_fdt, unsigned long orig_fdt_size,
+ void *fdt, int new_fdt_size, char *cmdline_ptr)
+{
+ int node, num_rsv;
+ int status;
+ u32 fdt_val32;
+ u64 fdt_val64;
+
+ /* Do some checks on provided FDT, if it exists: */
+ if (orig_fdt) {
+ if (fdt_check_header(orig_fdt)) {
+ efi_err("Device Tree header not valid!\n");
+ return EFI_LOAD_ERROR;
+ }
+ /*
+ * We don't get the size of the FDT if we get if from a
+ * configuration table:
+ */
+ if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) {
+ efi_err("Truncated device tree! foo!\n");
+ return EFI_LOAD_ERROR;
+ }
+ }
+
+ if (orig_fdt) {
+ status = fdt_open_into(orig_fdt, fdt, new_fdt_size);
+ } else {
+ status = fdt_create_empty_tree(fdt, new_fdt_size);
+ if (status == 0) {
+ /*
+ * Any failure from the following function is
+ * non-critical:
+ */
+ fdt_update_cell_size(fdt);
+ }
+ }
+
+ if (status != 0)
+ goto fdt_set_fail;
+
+ /*
+ * Delete all memory reserve map entries. When booting via UEFI,
+ * kernel will use the UEFI memory map to find reserved regions.
+ */
+ num_rsv = fdt_num_mem_rsv(fdt);
+ while (num_rsv-- > 0)
+ fdt_del_mem_rsv(fdt, num_rsv);
+
+ node = fdt_subnode_offset(fdt, 0, "chosen");
+ if (node < 0) {
+ node = fdt_add_subnode(fdt, 0, "chosen");
+ if (node < 0) {
+ /* 'node' is an error code when negative: */
+ status = node;
+ goto fdt_set_fail;
+ }
+ }
+
+ if (cmdline_ptr != NULL && strlen(cmdline_ptr) > 0) {
+ status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr,
+ strlen(cmdline_ptr) + 1);
+ if (status)
+ goto fdt_set_fail;
+ }
+
+ /* Add FDT entries for EFI runtime services in chosen node. */
+ node = fdt_subnode_offset(fdt, 0, "chosen");
+ fdt_val64 = cpu_to_fdt64((u64)(unsigned long)efi_system_table);
+
+ status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", fdt_val64);
+ if (status)
+ goto fdt_set_fail;
+
+ fdt_val64 = U64_MAX; /* placeholder */
+
+ status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
+ if (status)
+ goto fdt_set_fail;
+
+ fdt_val32 = U32_MAX; /* placeholder */
+
+ status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
+ if (status)
+ goto fdt_set_fail;
+
+ status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
+ if (status)
+ goto fdt_set_fail;
+
+ status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
+ if (status)
+ goto fdt_set_fail;
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && !efi_nokaslr) {
+ efi_status_t efi_status;
+
+ efi_status = efi_get_random_bytes(sizeof(fdt_val64),
+ (u8 *)&fdt_val64);
+ if (efi_status == EFI_SUCCESS) {
+ status = fdt_setprop_var(fdt, node, "kaslr-seed", fdt_val64);
+ if (status)
+ goto fdt_set_fail;
+ }
+ }
+
+ /* Shrink the FDT back to its minimum size: */
+ fdt_pack(fdt);
+
+ return EFI_SUCCESS;
+
+fdt_set_fail:
+ if (status == -FDT_ERR_NOSPACE)
+ return EFI_BUFFER_TOO_SMALL;
+
+ return EFI_LOAD_ERROR;
+}
+
+static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map)
+{
+ int node = fdt_path_offset(fdt, "/chosen");
+ u64 fdt_val64;
+ u32 fdt_val32;
+ int err;
+
+ if (node < 0)
+ return EFI_LOAD_ERROR;
+
+ fdt_val64 = cpu_to_fdt64((unsigned long)map->map);
+
+ err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-start", fdt_val64);
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ fdt_val32 = cpu_to_fdt32(map->map_size);
+
+ err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32);
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ fdt_val32 = cpu_to_fdt32(map->desc_size);
+
+ err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32);
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ fdt_val32 = cpu_to_fdt32(map->desc_ver);
+
+ err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", fdt_val32);
+ if (err)
+ return EFI_LOAD_ERROR;
+
+ return EFI_SUCCESS;
+}
+
+struct exit_boot_struct {
+ struct efi_boot_memmap *boot_memmap;
+ efi_memory_desc_t *runtime_map;
+ int runtime_entry_count;
+ void *new_fdt_addr;
+};
+
+static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
+{
+ struct exit_boot_struct *p = priv;
+
+ p->boot_memmap = map;
+
+ /*
+ * Update the memory map with virtual addresses. The function will also
+ * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
+ * entries so that we can pass it straight to SetVirtualAddressMap()
+ */
+ efi_get_virtmap(map->map, map->map_size, map->desc_size,
+ p->runtime_map, &p->runtime_entry_count);
+
+ return update_fdt_memmap(p->new_fdt_addr, map);
+}
+
+#ifndef MAX_FDT_SIZE
+# define MAX_FDT_SIZE SZ_2M
+#endif
+
+/*
+ * Allocate memory for a new FDT, then add EFI and commandline related fields
+ * to the FDT. This routine increases the FDT allocation size until the
+ * allocated memory is large enough. EFI allocations are in EFI_PAGE_SIZE
+ * granules, which are fixed at 4K bytes, so in most cases the first allocation
+ * should succeed. EFI boot services are exited at the end of this function.
+ * There must be no allocations between the get_memory_map() call and the
+ * exit_boot_services() call, so the exiting of boot services is very tightly
+ * tied to the creation of the FDT with the final memory map in it.
+ */
+static
+efi_status_t allocate_new_fdt_and_exit_boot(void *handle,
+ efi_loaded_image_t *image,
+ unsigned long *new_fdt_addr,
+ char *cmdline_ptr)
+{
+ unsigned long desc_size;
+ u32 desc_ver;
+ efi_status_t status;
+ struct exit_boot_struct priv;
+ unsigned long fdt_addr = 0;
+ unsigned long fdt_size = 0;
+
+ if (!efi_novamap) {
+ status = efi_alloc_virtmap(&priv.runtime_map, &desc_size,
+ &desc_ver);
+ if (status != EFI_SUCCESS) {
+ efi_err("Unable to retrieve UEFI memory map.\n");
+ return status;
+ }
+ }
+
+ /*
+ * Unauthenticated device tree data is a security hazard, so ignore
+ * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
+ * boot is enabled if we can't determine its state.
+ */
+ if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
+ efi_get_secureboot() != efi_secureboot_mode_disabled) {
+ if (strstr(cmdline_ptr, "dtb="))
+ efi_err("Ignoring DTB from command line.\n");
+ } else {
+ status = efi_load_dtb(image, &fdt_addr, &fdt_size);
+
+ if (status != EFI_SUCCESS && status != EFI_NOT_READY) {
+ efi_err("Failed to load device tree!\n");
+ goto fail;
+ }
+ }
+
+ if (fdt_addr) {
+ efi_info("Using DTB from command line\n");
+ } else {
+ /* Look for a device tree configuration table entry. */
+ fdt_addr = (uintptr_t)get_fdt(&fdt_size);
+ if (fdt_addr)
+ efi_info("Using DTB from configuration table\n");
+ }
+
+ if (!fdt_addr)
+ efi_info("Generating empty DTB\n");
+
+ efi_info("Exiting boot services...\n");
+
+ status = efi_allocate_pages(MAX_FDT_SIZE, new_fdt_addr, ULONG_MAX);
+ if (status != EFI_SUCCESS) {
+ efi_err("Unable to allocate memory for new device tree.\n");
+ goto fail;
+ }
+
+ status = update_fdt((void *)fdt_addr, fdt_size,
+ (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr);
+
+ if (status != EFI_SUCCESS) {
+ efi_err("Unable to construct new device tree.\n");
+ goto fail_free_new_fdt;
+ }
+
+ priv.new_fdt_addr = (void *)*new_fdt_addr;
+
+ status = efi_exit_boot_services(handle, &priv, exit_boot_func);
+
+ if (status == EFI_SUCCESS) {
+ efi_set_virtual_address_map_t *svam;
+
+ if (efi_novamap)
+ return EFI_SUCCESS;
+
+ /* Install the new virtual address map */
+ svam = efi_system_table->runtime->set_virtual_address_map;
+ status = svam(priv.runtime_entry_count * desc_size, desc_size,
+ desc_ver, priv.runtime_map);
+
+ /*
+ * We are beyond the point of no return here, so if the call to
+ * SetVirtualAddressMap() failed, we need to signal that to the
+ * incoming kernel but proceed normally otherwise.
+ */
+ if (status != EFI_SUCCESS) {
+ efi_memory_desc_t *p;
+ int l;
+
+ /*
+ * Set the virtual address field of all
+ * EFI_MEMORY_RUNTIME entries to U64_MAX. This will
+ * signal the incoming kernel that no virtual
+ * translation has been installed.
+ */
+ for (l = 0; l < priv.boot_memmap->map_size;
+ l += priv.boot_memmap->desc_size) {
+ p = (void *)priv.boot_memmap->map + l;
+
+ if (p->attribute & EFI_MEMORY_RUNTIME)
+ p->virt_addr = U64_MAX;
+ }
+ }
+ return EFI_SUCCESS;
+ }
+
+ efi_err("Exit boot services failed.\n");
+
+fail_free_new_fdt:
+ efi_free(MAX_FDT_SIZE, *new_fdt_addr);
+
+fail:
+ efi_free(fdt_size, fdt_addr);
+
+ efi_bs_call(free_pool, priv.runtime_map);
+
+ return EFI_LOAD_ERROR;
+}
+
+efi_status_t efi_boot_kernel(void *handle, efi_loaded_image_t *image,
+ unsigned long kernel_addr, char *cmdline_ptr)
+{
+ unsigned long fdt_addr;
+ efi_status_t status;
+
+ status = allocate_new_fdt_and_exit_boot(handle, image, &fdt_addr,
+ cmdline_ptr);
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to update FDT and exit boot services\n");
+ return status;
+ }
+
+ if (IS_ENABLED(CONFIG_ARM))
+ efi_handle_post_ebs_state();
+
+ efi_enter_kernel(kernel_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
+ /* not reached */
+}
+
+void *get_fdt(unsigned long *fdt_size)
+{
+ void *fdt;
+
+ fdt = get_efi_config_table(DEVICE_TREE_GUID);
+
+ if (!fdt)
+ return NULL;
+
+ if (fdt_check_header(fdt) != 0) {
+ efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n");
+ return NULL;
+ }
+ *fdt_size = fdt_totalsize(fdt);
+ return fdt;
+}