[PATCH 0/2] get sdm845 boards u-boot usable as a secondary bootloader

Dzmitry Sankouski dsankouski at gmail.com
Tue Jan 11 17:01:57 CET 2022


U-boot is intended to replace linux kernel in android boot image(ABL), and
it's FIT payload to replace initramfs file. The boot process is similar to
boot image with linux:
- android bootloader (ABL) unpacks android boot image
- ABL sets `linux,initrd-start property` in chosen node in unpacked FDT
- ABL sets x0 register to FDT address, and passes control to u-boot
- u-boot reads x0 register, and stores it in `abl_fdt_addr` env variable
- u-boot reads `linux,initrd-start` property,
and stores it in `abl_initrd_start_addr`

In this way, u-boot bootcmd relies on `abl_initrd_start_addr` env variable,
and boils down to `bootm $abl_initrd_start_addr`. If more control on
boot process is desired, pack a boot script in FIT image, and put it to
default configuration

Dzmitry Sankouski (2):
  soc: sdm845: implement ABL info collecting, add bootcommand and usage
    doc
  board: starqltechn: get board usable - fix defconfig and strip config
    options

 arch/arm/mach-snapdragon/init_sdm845.c | 60 ++++++++++++++++++++----
 configs/starqltechn_defconfig          | 12 +++--
 doc/board/qualcomm/sdm845.rst          | 63 +++++++++++++++++++++++++-
 include/configs/sdm845.h               |  5 ++
 4 files changed, 124 insertions(+), 16 deletions(-)

-- 
2.20.1



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