[Qemu-devel] [PATCH 6/6] hw/arm/boot: enable DTB support when booting ELF images

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

Add support for loading DTB images when booting ELF images via -kernel.
The DTB image is located at the next 4 KB boundary above the highest address
covered by the loaded ELF image.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 hw/arm/boot.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 8d8653978dfe..60c4f6af7884 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -458,7 +458,7 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     int kernel_size;
     int initrd_size;
     int is_linux = 0;
-    uint64_t elf_entry;
+    uint64_t elf_entry, elf_low_addr;
     int elf_machine;
     hwaddr entry, kernel_load_offset;
     int big_endian;
@@ -529,7 +529,21 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
 
     /* Assume that raw images are linux kernels, and ELF images are not.  */
     kernel_size = load_elf(info->kernel_filename, NULL, NULL, &elf_entry,
-                           NULL, NULL, big_endian, elf_machine, 1);
+                           &elf_low_addr, NULL, big_endian, elf_machine, 1);
+    if (kernel_size > 0 && have_dtb(info)) {
+        /* If we have a DTB in combination with an ELF executable image,
+         * put the DTB at the base of RAM like we do for bootloaders.
+         */
+        uint32_t dtb_size;
+
+        if (load_dtb(info->loader_start, info, &dtb_size)) {
+            exit(1);
+        }
+        if (info->loader_start + dtb_size > elf_low_addr) {
+            fprintf(stderr, "Image %s overlaps DTB\n", info->kernel_filename);
+            exit(1);
+        }
+    }
     entry = elf_entry;
     if (kernel_size < 0) {
         kernel_size = load_uimage(info->kernel_filename, &entry, NULL,
-- 
1.8.3.2