From: Icenowy Zheng icenowy@aosc.io
The ARMv7 start code has support for saving some boot params at the entry point, which is used by some SoCs to return to BROM.
Port this to ARM926EJ-S start code.
Signed-off-by: Icenowy Zheng icenowy@aosc.io Reviewed-by: Andre Przywara andre.przywara@arm.com Signed-off-by: Jesse Taube Mr.Bossman075@gmail.com --- V1->V2: * Nothing done V2->V3: * Nothing done --- arch/arm/cpu/arm926ejs/start.S | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S index 0afcc47aad..aca7793c57 100644 --- a/arch/arm/cpu/arm926ejs/start.S +++ b/arch/arm/cpu/arm926ejs/start.S @@ -17,6 +17,7 @@ #include <asm-offsets.h> #include <config.h> #include <common.h> +#include <linux/linkage.h>
/* ************************************************************************* @@ -32,8 +33,13 @@ */
.globl reset + .globl save_boot_params_ret + .type save_boot_params_ret,%function
reset: + /* Allow the board to save important registers */ + b save_boot_params +save_boot_params_ret: /* * set the cpu to SVC32 mode */ @@ -110,3 +116,16 @@ flush_dcache: #endif mov pc, lr /* back to my caller */ #endif /* CONFIG_IS_ENABLED(SKIP_LOWLEVEL_INIT) */ + +/************************************************************************* + * + * void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3) + * __attribute__((weak)); + * + * Stack pointer is not yet initialized at this moment + * Don't save anything to stack even if compiled with -O0 + * + *************************************************************************/ +WEAK(save_boot_params) + b save_boot_params_ret /* back to my caller */ +ENDPROC(save_boot_params)