Commit e11c6c27 authored by Simon Glass's avatar Simon Glass Committed by Hans de Goede
Browse files

arm: Allow lr to be saved by board code



The link register value can be required on some boards (e.g. FEL mode on
sunxi) so use a branch instruction to jump to save_boot_params() instead
of a branch link.

This requires a branch back to save_boot_params_ret so adjust the users
to deal with this. For exynos just drop the function since it doesn't
do anything.
Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
Acked-by: default avatarSiarhei Siamashka <siarhei.siamashka@gmail.com>
Acked-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent c924e2a8
......@@ -309,4 +309,3 @@ void board_init_r(gd_t *id, ulong dest_addr)
while (1)
;
}
void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3) {}
......@@ -19,7 +19,7 @@
ENTRY(save_boot_params)
ldr r1, =OMAP_SRAM_SCRATCH_BOOT_PARAMS
str r0, [r1]
bx lr
b save_boot_params_ret
ENDPROC(save_boot_params)
ENTRY(set_pl310_ctrl_reg)
......
......@@ -23,7 +23,7 @@ ENTRY(save_boot_params)
ldr r5, [r0, #0x4]
and r5, r5, #0xff
str r5, [r4]
bx lr
b save_boot_params_ret
ENDPROC(save_boot_params)
#endif
......
......@@ -31,9 +31,12 @@
*************************************************************************/
.globl reset
.globl save_boot_params_ret
reset:
bl save_boot_params
/* Allow the board to save important registers */
b save_boot_params
save_boot_params_ret:
/*
* disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
* except if in HYP mode already
......@@ -96,7 +99,7 @@ ENDPROC(c_runtime_cpu_setup)
*
*************************************************************************/
ENTRY(save_boot_params)
bx lr @ back to my caller
b save_boot_params_ret @ back to my caller
ENDPROC(save_boot_params)
.weak save_boot_params
......
......@@ -142,6 +142,21 @@ void flush_l3_cache(void);
#ifndef __ASSEMBLY__
/**
* save_boot_params() - Save boot parameters before starting reset sequence
*
* If you provide this function it will be called immediately U-Boot starts,
* both for SPL and U-Boot proper.
*
* All registers are unchanged from U-Boot entry. No registers need be
* preserved.
*
* This is not a normal C function. There is no stack. Return by branching to
* save_boot_params_ret.
*
* void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3);
*/
#define isb() __asm__ __volatile__ ("" : : : "memory")
#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
......
......@@ -37,7 +37,8 @@ ih_magic: /* IH_MAGIC in big endian from include/image.h */
.global save_boot_params
save_boot_params:
/* Get return address */
ldr lr, =save_boot_params_ret
/* Copy valid attached kernel to address KERNEL_ADDRESS */
......
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