diff --git a/elfloader-tool/include/elfloader_common.h b/elfloader-tool/include/elfloader_common.h
index 84ae4eb7..63758849 100644
--- a/elfloader-tool/include/elfloader_common.h
+++ b/elfloader-tool/include/elfloader_common.h
@@ -7,6 +7,7 @@
#pragma once
+#include <stdbool.h>
#include <types.h>
typedef uintptr_t paddr_t;
@@ -41,6 +42,9 @@ typedef uintptr_t vaddr_t;
typedef struct {
paddr_t phys_base;
size_t size;
+#ifdef CONFIG_ELFLOADER_INCLUDE_DTB
+ bool is_from_cpio;
+#endif
} dtb_info_t;
/*
diff --git a/elfloader-tool/src/common.c b/elfloader-tool/src/common.c
index 0ae8edd9..1f7cff60 100644
--- a/elfloader-tool/src/common.c
+++ b/elfloader-tool/src/common.c
@@ -351,6 +351,109 @@ static int load_elf(
return 0;
}
+/*
+ * Load the DTB
+ */
+static int load_dtb(
+ void const *cpio,
+ size_t cpio_len,
+ paddr_t dtb_load_phys,
+ dtb_info_t *dtb_info)
+{
+ int ret;
+
+ void const *dtb = NULL;
+
+#ifdef CONFIG_ELFLOADER_INCLUDE_DTB
+
+ /* A DTB present in the CPIO archive takes preference over a DTB passed
+ * from the bootloder.
+ */
+
+ printf("Looking for DTB in CPIO archive...");
+ /* Note the lack of newline in the above printf(). Normally, fflush(stdout)
+ * must be called to ensure that the message shows up on a line-buffered
+ * stream, which is the POSIX default on terminal devices). However, we are
+ * freestanding (on the "bare metal"), and use our own unbuffered printf()
+ * implementation.
+ */
+
+ unsigned long cpio_dtb_size = 0;
+ dtb = cpio_get_file(cpio, cpio_len, "kernel.dtb", &cpio_dtb_size);
+ if (!dtb) {
+ printf("not found.\n");
+ } else {
+ printf("found at %p.\n", dtb);
+ if (dtb_info) {
+ dtb_info->is_from_cpio = true;
+ }
+ }
+
+#endif /* CONFIG_ELFLOADER_INCLUDE_DTB */
+
+ /* If we don't have a DTB here, use the one a bootloader might have
+ * provided. Since 0 is a valid physical address, the size field is used to
+ * determin if the address is valid. A size of -1 indicates, that the actual
+ * size is not known - which is usually the case, because a bootloader often
+ * just passes an address.
+ */
+ if (!dtb) {
+ if (0 == dtb_info->size) {
+ /* Not having a DTB is not an error. With dtb_info->size still set
+ * to zero, the caller can find out that no DTB was loaded and then
+ * act accordingly.
+ */
+ printf("No DTB available\n");
+ dtb_info->phys_base = 0;
+ return 0;
+ }
+
+ printf("Loading DTB passed from bootloader at %p\n",
+ dtb_info->phys_base);
+
+ dtb = (void const *)(dtb_info->phys_base);
+ }
+
+ size_t dtb_size = fdt_size((void *)dtb);
+ if (0 == dtb_size) {
+ printf("ERROR: Invalid device tree blob supplied\n");
+ return -1;
+ }
+
+#ifdef CONFIG_ELFLOADER_INCLUDE_DTB
+
+ if (dtb_info->is_from_cpio && (dtb_size > cpio_dtb_size)) {
+ printf("ERROR: parsed device tree is larger (%zu byte) than CPIO file (%zu byte)\n",
+ dtb_size, cpio_dtb_size);
+ return -1;
+ }
+
+#endif /* CONFIG_ELFLOADER_INCLUDE_DTB */
+
+ /* Move the DTB out of the way. Check that the physical destination
+ * location is sane.
+ */
+ paddr_t dtb_phys_end = dtb_load_phys + dtb_size;
+ ret = ensure_phys_range_valid(dtb_load_phys, dtb_phys_end);
+ if (0 != ret) {
+ printf("ERROR: Physical target address of DTB is invalid\n");
+ return -1;
+ }
+
+ memmove((void *)dtb_load_phys, dtb, dtb_size);
+
+ printf("Loaded DTB from %p.\n", dtb);
+ printf(" paddr=[%p..%p]\n", dtb_load_phys, dtb_phys_end - 1);
+
+ /* Set DTB values for caller. */
+ if (dtb_info) {
+ dtb_info->phys_base = dtb_load_phys;
+ dtb_info->size = dtb_size;
+ }
+
+ return 0;
+}
+
/*
* ELF-loader for ARM systems.
*
@@ -388,10 +491,7 @@ int load_images(
{
int ret;
uint64_t kernel_phys_start, kernel_phys_end;
- uintptr_t dtb_phys_start, dtb_phys_end;
- paddr_t next_phys_addr;
const char *elf_filename;
- int has_dtb_cpio = 0;
void const *cpio = _archive_start;
size_t cpio_len = _archive_start_end - _archive_start;
@@ -428,72 +528,23 @@ int load_images(
return -1;
}
- void const *dtb = NULL;
-
-#ifdef CONFIG_ELFLOADER_INCLUDE_DTB
-
- printf("Looking for DTB in CPIO archive...");
- /*
- * Note the lack of newline in the above printf(). Normally one would
- * have an fflush(stdout) here to ensure that the message shows up on a
- * line-buffered stream (which is the POSIX default on terminal
- * devices). But we are freestanding (on the "bare metal"), and using
- * our own unbuffered printf() implementation.
+ /* Load the DTB first, because this allows extracting further platform
+ * information from it, which may affect the system setup. The DTB is put
+ * after the kernel image, because this ensures it is in a place well
+ * aligned with our memory usage.
*/
- dtb = cpio_get_file(cpio, cpio_len, "kernel.dtb", NULL);
- if (dtb == NULL) {
- printf("not found.\n");
- } else {
- has_dtb_cpio = 1;
- printf("found at %p.\n", dtb);
- }
-
-#endif /* CONFIG_ELFLOADER_INCLUDE_DTB */
-
- /* If we don't have a DTB here, use the one a bootloader might have
- * provided. Since 0 is a valid physical address, the size field is used to
- * determin if the address is valid. A size of -1 indicates, that the actual
- * size is not known - which is usually the case, because a bootloader often
- * just passes an address.
- */
- if (!dtb && (dtb_info->size > 0)) {
- dtb = (void const *)dtb_info->phys_base;
+ paddr_t next_phys_addr = ROUND_UP(kernel_phys_end, PAGE_BITS);
+ ret = load_dtb(cpio, cpio_len, next_phys_addr, dtb_info);
+ if (ret != 0) {
+ printf("ERROR: Could not load DTB\n");
+ return -1;
}
- /*
- * Move the DTB out of the way, if it's present.
+ /* It's not an error here if no DTB was loaded. Eventually, the system that
+ * we are loading has to decide if it can handle this.
*/
- if (dtb) {
- /* keep it page aligned */
- next_phys_addr = dtb_phys_start = ROUND_UP(kernel_phys_end, PAGE_BITS);
-
- size_t dtb_size = fdt_size(dtb);
- if (0 == dtb_size) {
- printf("ERROR: Invalid device tree blob supplied\n");
- return -1;
- }
-
- /* Make sure this is a sane thing to do */
- ret = ensure_phys_range_valid(next_phys_addr,
- next_phys_addr + dtb_size);
- if (0 != ret) {
- printf("ERROR: Physical address of DTB invalid\n");
- return -1;
- }
-
- memmove((void *)next_phys_addr, dtb, dtb_size);
- next_phys_addr += dtb_size;
- next_phys_addr = ROUND_UP(next_phys_addr, PAGE_BITS);
- dtb_phys_end = next_phys_addr;
-
- printf("Loaded DTB from %p.\n", dtb);
- printf(" paddr=[%p..%p]\n", dtb_phys_start, dtb_phys_end - 1);
- dtb_info->phys_base = dtb_phys_start;
- dtb_info->size = dtb_size;
- } else {
- dtb_info->phys_base = 0;
- dtb_info->size = 0;
- next_phys_addr = ROUND_UP(kernel_phys_end, PAGE_BITS);
+ if (dtb_info->size > 0) {
+ next_phys_addr = ROUND_UP(next_phys_addr + dtb_info->size, PAGE_BITS);
}
/* Load the kernel */
@@ -531,10 +582,12 @@ int load_images(
cpio_get_entry(cpio, cpio_len, 1, &elf_filename, NULL);
ret = strcmp(elf_filename, "kernel.dtb");
if (0 != ret) {
- if (has_dtb_cpio) {
+#ifdef CONFIG_ELFLOADER_INCLUDE_DTB
+ if (dtb_info->is_from_cpio) {
printf("ERROR: Kernel DTB not second image in archive\n");
return -1;
}
+#endif
user_elf_offset = 1;
}