Re: [PATCH 3/4] arm: mvebu: Add documentation for save_boot_params() function

On 21.10.21 16:46, Pali Rohár wrote:

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

Thanks, Stefan

---

arch/arm/mach-mvebu/lowlevel_spl.S | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/arch/arm/mach-mvebu/lowlevel_spl.S b/arch/arm/mach-mvebu/lowlevel_spl.S index dde77b765214..39d42912c49f 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

Viele Grüße, Stefan