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-rw-r--r--kexec/dt-ops.c176
1 files changed, 176 insertions, 0 deletions
diff --git a/kexec/dt-ops.c b/kexec/dt-ops.c
new file mode 100644
index 0000000..0a96b75
--- /dev/null
+++ b/kexec/dt-ops.c
@@ -0,0 +1,176 @@
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <libfdt.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "kexec.h"
+#include "dt-ops.h"
+
+static const char n_chosen[] = "chosen";
+
+static const char p_bootargs[] = "bootargs";
+static const char p_initrd_start[] = "linux,initrd-start";
+static const char p_initrd_end[] = "linux,initrd-end";
+
+int dtb_set_initrd(char **dtb, off_t *dtb_size, off_t start, off_t end)
+{
+ int result;
+ uint64_t value;
+
+ dbgprintf("%s: start %jd, end %jd, size %jd (%jd KiB)\n",
+ __func__, (intmax_t)start, (intmax_t)end,
+ (intmax_t)(end - start),
+ (intmax_t)(end - start) / 1024);
+
+ value = cpu_to_fdt64(start);
+
+ result = dtb_set_property(dtb, dtb_size, n_chosen, p_initrd_start,
+ &value, sizeof(value));
+
+ if (result)
+ return result;
+
+ value = cpu_to_fdt64(end);
+
+ result = dtb_set_property(dtb, dtb_size, n_chosen, p_initrd_end,
+ &value, sizeof(value));
+
+ if (result) {
+ dtb_delete_property(*dtb, n_chosen, p_initrd_start);
+ return result;
+ }
+
+ return 0;
+}
+
+void dtb_clear_initrd(char **dtb, off_t *dtb_size)
+{
+ dtb_delete_property(*dtb, n_chosen, p_initrd_start);
+ dtb_delete_property(*dtb, n_chosen, p_initrd_end);
+}
+
+int dtb_set_bootargs(char **dtb, off_t *dtb_size, const char *command_line)
+{
+ return dtb_set_property(dtb, dtb_size, n_chosen, p_bootargs,
+ command_line, strlen(command_line) + 1);
+}
+
+int dtb_set_property(char **dtb, off_t *dtb_size, const char *node,
+ const char *prop, const void *value, int value_len)
+{
+ int result;
+ int nodeoffset;
+ void *new_dtb;
+ int new_size;
+ char *new_node = NULL;
+
+ value_len = FDT_TAGALIGN(value_len);
+
+ new_size = FDT_TAGALIGN(*dtb_size + fdt_node_len(node)
+ + fdt_prop_len(prop, value_len));
+
+ new_dtb = malloc(new_size);
+
+ if (!new_dtb) {
+ dbgprintf("%s: malloc failed\n", __func__);
+ return -ENOMEM;
+ }
+
+ result = fdt_open_into(*dtb, new_dtb, new_size);
+
+ if (result) {
+ dbgprintf("%s: fdt_open_into failed: %s\n", __func__,
+ fdt_strerror(result));
+ goto on_error;
+ }
+
+ new_node = malloc(strlen("/") + strlen(node) + 1);
+ if (!new_node) {
+ dbgprintf("%s: malloc failed\n", __func__);
+ result = -ENOMEM;
+ goto on_error;
+ }
+
+ strcpy(new_node, "/");
+ strcat(new_node, node);
+
+ nodeoffset = fdt_path_offset(new_dtb, new_node);
+
+ if (nodeoffset == -FDT_ERR_NOTFOUND) {
+ result = fdt_add_subnode(new_dtb, 0, node);
+
+ if (result < 0) {
+ dbgprintf("%s: fdt_add_subnode failed: %s\n", __func__,
+ fdt_strerror(result));
+ goto on_error;
+ }
+ nodeoffset = result;
+ } else if (nodeoffset < 0) {
+ dbgprintf("%s: fdt_path_offset failed: %s\n", __func__,
+ fdt_strerror(nodeoffset));
+ goto on_error;
+ }
+
+ result = fdt_setprop(new_dtb, nodeoffset, prop, value, value_len);
+
+ if (result) {
+ dbgprintf("%s: fdt_setprop failed: %s\n", __func__,
+ fdt_strerror(result));
+ goto on_error;
+ }
+
+ /*
+ * Can't call free on dtb since dtb may have been mmaped by
+ * slurp_file().
+ */
+
+ result = fdt_pack(new_dtb);
+
+ if (result)
+ dbgprintf("%s: Unable to pack device tree: %s\n", __func__,
+ fdt_strerror(result));
+
+ *dtb = new_dtb;
+ *dtb_size = fdt_totalsize(*dtb);
+
+ return 0;
+
+on_error:
+ free(new_dtb);
+ free(new_node);
+ return result;
+}
+
+int dtb_delete_property(char *dtb, const char *node, const char *prop)
+{
+ int result, nodeoffset;
+ char *new_node = NULL;
+
+ new_node = malloc(strlen("/") + strlen(node) + 1);
+ if (!new_node) {
+ dbgprintf("%s: malloc failed\n", __func__);
+ return -ENOMEM;
+ }
+
+ strcpy(new_node, "/");
+ strcat(new_node, node);
+
+ nodeoffset = fdt_path_offset(dtb, new_node);
+ if (nodeoffset < 0) {
+ dbgprintf("%s: fdt_path_offset failed: %s\n", __func__,
+ fdt_strerror(nodeoffset));
+ free(new_node);
+ return nodeoffset;
+ }
+
+ result = fdt_delprop(dtb, nodeoffset, prop);
+
+ if (result)
+ dbgprintf("%s: fdt_delprop failed: %s\n", __func__,
+ fdt_strerror(nodeoffset));
+
+ free(new_node);
+ return result;
+}