hw/arm/boot: Allow boards to provide an fdt blob
If no fdt is provided on command line and the new field
get_dtb in struct arm_boot_info is set then call it to
get a device tree blob.
Signed-off-by: John Rigby <john.rigby@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Message-id: 1385140638-10444-4-git-send-email-peter.maydell@linaro.org
[PMM: minor tweaks and cleanup]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 583ec79..55d552f 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -228,23 +228,31 @@
static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo)
{
void *fdt = NULL;
- char *filename;
int size, rc;
uint32_t acells, scells;
- filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
- if (!filename) {
- fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
- goto fail;
- }
+ if (binfo->dtb_filename) {
+ char *filename;
+ filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
+ if (!filename) {
+ fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
+ goto fail;
+ }
- fdt = load_device_tree(filename, &size);
- if (!fdt) {
- fprintf(stderr, "Couldn't open dtb file %s\n", filename);
+ fdt = load_device_tree(filename, &size);
+ if (!fdt) {
+ fprintf(stderr, "Couldn't open dtb file %s\n", filename);
+ g_free(filename);
+ goto fail;
+ }
g_free(filename);
- goto fail;
+ } else if (binfo->get_dtb) {
+ fdt = binfo->get_dtb(binfo, &size);
+ if (!fdt) {
+ fprintf(stderr, "Board was unable to create a dtb blob\n");
+ goto fail;
+ }
}
- g_free(filename);
acells = qemu_devtree_getprop_cell(fdt, "/", "#address-cells");
scells = qemu_devtree_getprop_cell(fdt, "/", "#size-cells");
@@ -438,7 +446,7 @@
/* for device tree boot, we pass the DTB directly in r2. Otherwise
* we point to the kernel args.
*/
- if (info->dtb_filename) {
+ if (info->dtb_filename || info->get_dtb) {
/* Place the DTB after the initrd in memory. Note that some
* kernels will trash anything in the 4K page the initrd
* ends in, so make sure the DTB isn't caught up in that.
diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h
index ecbbba8..cbbf4ca 100644
--- a/include/hw/arm/arm.h
+++ b/include/hw/arm/arm.h
@@ -50,6 +50,13 @@
const struct arm_boot_info *info);
void (*secondary_cpu_reset_hook)(ARMCPU *cpu,
const struct arm_boot_info *info);
+ /* if a board is able to create a dtb without a dtb file then it
+ * sets get_dtb. This will only be used if no dtb file is provided
+ * by the user. On success, sets *size to the length of the created
+ * dtb, and returns a pointer to it. (The caller must free this memory
+ * with g_free() when it has finished with it.) On failure, returns NULL.
+ */
+ void *(*get_dtb)(const struct arm_boot_info *info, int *size);
/* if a board needs to be able to modify a device tree provided by
* the user it should implement this hook.
*/
