diff options
| author | Dzmitry Sankouski <dsankouski@gmail.com> | 2022-02-22 21:49:52 +0300 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2022-04-04 14:53:26 -0400 |
| commit | 12a3e1ada06c702c403cf1eebb063ef7a34688cd (patch) | |
| tree | d58972054d39b90b0b0a92d5c9b093d0547264a6 /boot | |
| parent | 5c9b420ada3b4f2a08da4789571f0ea373881565 (diff) | |
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>
Diffstat (limited to 'boot')
| -rw-r--r-- | boot/Kconfig | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/boot/Kconfig b/boot/Kconfig index 394b26f246..ec5b956490 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -1192,4 +1192,28 @@ config DEFAULT_FDT_FILE help This option is used to set the default fdt file to boot OS. +config SAVE_PREV_BL_FDT_ADDR + depends on ARM + bool "Saves fdt address, passed by the previous bootloader, to env var" + help + When u-boot is used as a chain-loaded bootloader (replacing OS kernel), + enable this option to save fdt address, passed by the + previous bootloader for future use. + Address is saved to `prevbl_fdt_addr` environment variable. + + If no fdt was provided by previous bootloader, no env variables + will be created. + +config SAVE_PREV_BL_INITRAMFS_START_ADDR + depends on ARM + bool "Saves initramfs address, passed by the previous bootloader, to env var" + help + When u-boot is used as a chain-loaded bootloader(replacing OS kernel), + enable this option to save initramfs address, passed by the + previous bootloader for future use. + Address is saved to `prevbl_initrd_start_addr` environment variable. + + If no initramfs was provided by previous bootloader, no env variables + will be created. + endmenu # Booting |