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| author | Pali Rohár | 2021-10-21 16:46:08 +0200 |
|---|---|---|
| committer | Stefan Roese | 2021-10-28 10:33:32 +0200 |
| commit | 701769d87ea3006103c93fd0ecc26875e02d461f (patch) | |
| tree | de82f7a64214287a7974e1e54d15cc87d4381f1a /arch/arm/mach-mvebu | |
| parent | e58f08b479bb512e4976fc2481657f6cfaf7e7b5 (diff) | |
arm: mvebu: Add documentation for save_boot_params() function
Important detail is availability of kwbimage BIN header arguments passed
via r0 and r1 registers by BootROM.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Diffstat (limited to 'arch/arm/mach-mvebu')
| -rw-r--r-- | arch/arm/mach-mvebu/lowlevel_spl.S | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/mach-mvebu/lowlevel_spl.S b/arch/arm/mach-mvebu/lowlevel_spl.S index dde77b76521..501c239e9d3 100644 --- a/arch/arm/mach-mvebu/lowlevel_spl.S +++ b/arch/arm/mach-mvebu/lowlevel_spl.S @@ -3,6 +3,15 @@ #include <config.h> #include <linux/linkage.h> +/* + * BootROM loads the header part of kwbimage into L2 cache. BIN header usually + * contains U-Boot SPL, optionally it can also contain additional arguments. + * The number of these arguments is in r0, pointer to the argument array in r1. + * BootROM expects executable BIN header code to return to address stored in lr. + * Other registers (r2 - r12) must be preserved. We save all registers to + * CONFIG_SPL_BOOTROM_SAVE address. BIN header arguments (passed via r0 and r1) + * are currently not used by U-Boot SPL binary. + */ ENTRY(save_boot_params) stmfd sp!, {r0 - r12, lr} /* @ save registers on stack */ ldr r12, =CONFIG_SPL_BOOTROM_SAVE |