* [U-Boot] SPL: branching out of start.S
@ 2011-11-23 3:09 jonsmirl at gmail.com
2011-11-23 12:13 ` Marek Vasut
0 siblings, 1 reply; 3+ messages in thread
From: jonsmirl at gmail.com @ 2011-11-23 3:09 UTC (permalink / raw)
To: u-boot
The way the SPL code is setup right now it only works in the
CONFIG_NAND_SPL case. The chip I'm working on, the lpc313x, can SPL
from six different sources. I've implemented the secondary loader code
in board_init_r in cpu/arm926ejs/lpc313x/spl.c. I needed to modify
start.S so that the jump to board_init_r works correctly in the SPL
case.
Is it possible to merge things further and get rid of this special case?
#ifdef CONFIG_NAND_SPL
ldr r0, _nand_boot_ofs
mov pc, r0
_nand_boot_ofs:
.word nand_boot
#else
ldr r0, _board_init_r_ofs
ldr r1, _TEXT_BASE
add lr, r0, r1
add lr, lr, r9
---------------------------------------------------------------------------
diff --git a/arch/arm/cpu/arm926ejs/start.S b/arch/arm/cpu/arm926ejs/start.S
index 5e30745..0f97979 100644
--- a/arch/arm/cpu/arm926ejs/start.S
+++ b/arch/arm/cpu/arm926ejs/start.S
@@ -64,6 +64,13 @@ _start:
b reset
#endif
#ifdef CONFIG_SPL_BUILD
+#ifdef CONFIG_LPC313x_BOOT_HEADER
+ .word 0x41676d69 /* image magic number, imgA */
+ .word 0,0,0,0,0
+ .word 0x0000000A /*Plain text no CRC check*/
+ .word (__initial_boot_image_size) /* image length */
+ .word 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+#else
/* No exception handlers in preloader */
ldr pc, _hang
ldr pc, _hang
@@ -83,6 +90,7 @@ _hang:
.word 0x12345678
.word 0x12345678
.word 0x12345678
+#endif
#else
ldr pc, _undefined_instruction
ldr pc, _software_interrupt
@@ -126,7 +134,11 @@ _fiq:
.globl _TEXT_BASE
_TEXT_BASE:
+#ifdef CONFIG_SPL_BUILD
+ .word CONFIG_SPL_TEXT_BASE
+#else
.word CONFIG_SYS_TEXT_BASE
+#endif
/*
* These are defined in the board-specific linker script.
@@ -210,6 +222,7 @@ relocate_code:
stack_setup:
mov sp, r4
+ mov r9, #0x00000000 /* relocation offset starts at zero */
adr r0, _start
cmp r0, r6
beq clear_bss /* skip relocation */
--
Jon Smirl
jonsmirl at gmail.com
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [U-Boot] SPL: branching out of start.S
2011-11-23 3:09 [U-Boot] SPL: branching out of start.S jonsmirl at gmail.com
@ 2011-11-23 12:13 ` Marek Vasut
2011-11-23 12:40 ` jonsmirl at gmail.com
0 siblings, 1 reply; 3+ messages in thread
From: Marek Vasut @ 2011-11-23 12:13 UTC (permalink / raw)
To: u-boot
> The way the SPL code is setup right now it only works in the
> CONFIG_NAND_SPL case. The chip I'm working on, the lpc313x, can SPL
> from six different sources. I've implemented the secondary loader code
> in board_init_r in cpu/arm926ejs/lpc313x/spl.c. I needed to modify
> start.S so that the jump to board_init_r works correctly in the SPL
> case.
>
> Is it possible to merge things further and get rid of this special case?
>
> #ifdef CONFIG_NAND_SPL
> ldr r0, _nand_boot_ofs
> mov pc, r0
>
> _nand_boot_ofs:
> .word nand_boot
> #else
> ldr r0, _board_init_r_ofs
> ldr r1, _TEXT_BASE
> add lr, r0, r1
> add lr, lr, r9
>
> ---------------------------------------------------------------------------
>
> diff --git a/arch/arm/cpu/arm926ejs/start.S
> b/arch/arm/cpu/arm926ejs/start.S index 5e30745..0f97979 100644
> --- a/arch/arm/cpu/arm926ejs/start.S
> +++ b/arch/arm/cpu/arm926ejs/start.S
> @@ -64,6 +64,13 @@ _start:
> b reset
> #endif
> #ifdef CONFIG_SPL_BUILD
> +#ifdef CONFIG_LPC313x_BOOT_HEADER
> + .word 0x41676d69 /* image magic number, imgA */
> + .word 0,0,0,0,0
> + .word 0x0000000A /*Plain text no CRC check*/
> + .word (__initial_boot_image_size) /* image length */
> + .word 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
> +#else
> /* No exception handlers in preloader */
> ldr pc, _hang
> ldr pc, _hang
> @@ -83,6 +90,7 @@ _hang:
> .word 0x12345678
> .word 0x12345678
> .word 0x12345678
> +#endif
> #else
> ldr pc, _undefined_instruction
> ldr pc, _software_interrupt
> @@ -126,7 +134,11 @@ _fiq:
>
> .globl _TEXT_BASE
> _TEXT_BASE:
> +#ifdef CONFIG_SPL_BUILD
> + .word CONFIG_SPL_TEXT_BASE
> +#else
> .word CONFIG_SYS_TEXT_BASE
> +#endif
>
> /*
> * These are defined in the board-specific linker script.
> @@ -210,6 +222,7 @@ relocate_code:
> stack_setup:
> mov sp, r4
>
> + mov r9, #0x00000000 /* relocation offset starts at zero
> */ adr r0, _start
> cmp r0, r6
> beq clear_bss /* skip relocation */
You can supply your own, separate, start.S for SPL.
M
^ permalink raw reply [flat|nested] 3+ messages in thread
* [U-Boot] SPL: branching out of start.S
2011-11-23 12:13 ` Marek Vasut
@ 2011-11-23 12:40 ` jonsmirl at gmail.com
0 siblings, 0 replies; 3+ messages in thread
From: jonsmirl at gmail.com @ 2011-11-23 12:40 UTC (permalink / raw)
To: u-boot
On Wed, Nov 23, 2011 at 7:13 AM, Marek Vasut <marek.vasut@gmail.com> wrote:
>> Is it possible to merge things further and get rid of this special case?
I'd rather stick with the common code and not proliferate start.S
versions. The main bug right now is that r9 is not zero'd for the SPL
case causing a random offset to be added.
But more consolidation is possible:
ldr r0, _board_init_r_ofs ldr r1, _TEXT_BASE add lr, r0, r1 add lr,
lr, r9 /* setup parameters for board_init_r */ mov r0, r5 /* gd_t
*/ mov r1, r6 /* dest_addr */ /* jump to it ... */ mov pc, lr
_board_init_r_ofs:#ifdef CONFIG_NAND_SPL
.word nand_boot - _start
#else
.word board_init_r - _start#endif
Even more if nand_boot is wrapped and renamed board_init_r().
--
Jon Smirl
jonsmirl at gmail.com
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-11-23 3:09 [U-Boot] SPL: branching out of start.S jonsmirl at gmail.com
2011-11-23 12:13 ` Marek Vasut
2011-11-23 12:40 ` jonsmirl at gmail.com
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