arm: init: save previous bootloader data
When u-boot is used as a chain-loaded bootloader (replacing OS kernel),
previous bootloader leaves data in RAM, that can be reused.
For example, on recent arm linux system, when chainloading u-boot,
there are initramfs and fdt in RAM prepared for OS booting. Initramfs
may be modified to store u-boot's payload, thus providing the ability to
use chainloaded u-boot to boot OS without any storage support.
Two config options added:
- SAVE_PREV_BL_INITRAMFS_START_ADDR
saves initramfs start address to 'prevbl_initrd_start_addr' environment
variable
- SAVE_PREV_BL_FDT_ADDR
saves fdt address to 'prevbl_fdt_addr' environment variable
Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
diff --git a/common/board_r.c b/common/board_r.c
index b92c1bb..8dc87ed 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -445,6 +445,11 @@
env_set_hex("fdtcontroladdr",
(unsigned long)map_to_sysmem(gd->fdt_blob));
+ #if (CONFIG_IS_ENABLED(SAVE_PREV_BL_INITRAMFS_START_ADDR) || \
+ CONFIG_IS_ENABLED(SAVE_PREV_BL_FDT_ADDR))
+ save_prev_bl_data();
+ #endif
+
/* Initialize from environment */
image_load_addr = env_get_ulong("loadaddr", 16, image_load_addr);