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arm: move C runtime setup code in crt0.S
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Move all the C runtime setup code from every start.S
in arch/arm into arch/arm/lib/crt0.S. This covers
the code sequence from setting up the initial stack
to calling into board_init_r().

Also, rewrite the C runtime setup and make functions
board_init_*() and relocate_code() behave according to
normal C semantics (no jumping across the C stack any
more, etc).

Some SPL targets had to be touched because they use
start.S explicitly or for some reason; the relevant
maintainers and custodians are cc:ed.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
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albert-aribaud-u-boot committed Jan 8, 2013
1 parent 7528cf5 commit e05e5de
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Showing 21 changed files with 326 additions and 678 deletions.
71 changes: 14 additions & 57 deletions arch/arm/cpu/arm1136/start.S
Expand Up @@ -165,13 +165,7 @@ next:
bl cpu_init_crit
#endif

/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
ldr r0,=0x00000000

bl board_init_f
bl _main

/*------------------------------------------------------------------------------*/

Expand All @@ -188,14 +182,10 @@ relocate_code:
mov r5, r1 /* save addr of gd */
mov r6, r2 /* save addr of destination */

/* Set up the stack */
stack_setup:
mov sp, r4

adr r0, _start
cmp r0, r6
moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
beq clear_bss /* skip relocation */
beq relocate_done /* skip relocation */
mov r1, r6 /* r1 <- scratch for copy_loop */
ldr r3, _image_copy_end_ofs
add r2, r0, r3 /* r2 <- source end address */
Expand Down Expand Up @@ -245,62 +235,29 @@ fixnext:
add r2, r2, #8 /* each rel.dyn entry is 8 bytes */
cmp r2, r3
blo fixloop
b clear_bss
bx lr

#endif

relocate_done:

bx lr

#ifndef CONFIG_SPL_BUILD

_rel_dyn_start_ofs:
.word __rel_dyn_start - _start
_rel_dyn_end_ofs:
.word __rel_dyn_end - _start
_dynsym_start_ofs:
.word __dynsym_start - _start
#endif

clear_bss:
#ifdef CONFIG_SPL_BUILD
/* No relocation for SPL */
ldr r0, =__bss_start
ldr r1, =__bss_end__
#else
ldr r0, _bss_start_ofs
ldr r1, _bss_end_ofs
mov r4, r6 /* reloc addr */
add r0, r0, r4
add r1, r1, r4
#endif
mov r2, #0x00000000 /* clear */

clbss_l:cmp r0, r1 /* clear loop... */
bhs clbss_e /* if reached end of bss, exit */
str r2, [r0]
add r0, r0, #4
b clbss_l
clbss_e:

/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
#ifdef CONFIG_NAND_SPL
ldr r0, _nand_boot_ofs
mov pc, r0
.globl c_runtime_cpu_setup
c_runtime_cpu_setup:

_nand_boot_ofs:
.word nand_boot
#else
jump_2_ram:
ldr r0, _board_init_r_ofs
adr r1, _start
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:
.word board_init_r - _start
#endif
bx lr

/*
*************************************************************************
Expand Down
62 changes: 9 additions & 53 deletions arch/arm/cpu/arm1176/start.S
Expand Up @@ -224,12 +224,7 @@ skip_tcmdisable:
*/
bl lowlevel_init /* go setup pll,mux,memory */

/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
ldr r0,=0x00000000
bl board_init_f
bl _main

/*------------------------------------------------------------------------------*/

Expand All @@ -246,14 +241,10 @@ relocate_code:
mov r5, r1 /* save addr of gd */
mov r6, r2 /* save addr of destination */

/* Set up the stack */
stack_setup:
mov sp, r4

adr r0, _start
cmp r0, r6
moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
beq clear_bss /* skip relocation */
beq relocate_done /* skip relocation */
mov r1, r6 /* r1 <- scratch for copy_loop */
ldr r3, _bss_start_ofs
add r2, r0, r3 /* r2 <- source end address */
Expand Down Expand Up @@ -343,49 +334,9 @@ mmu_enable:
skip_hw_init:
#endif

clear_bss:
#ifndef CONFIG_SPL_BUILD
ldr r0, _bss_start_ofs
ldr r1, _bss_end_ofs
mov r4, r6 /* reloc addr */
add r0, r0, r4
add r1, r1, r4
mov r2, #0x00000000 /* clear */

clbss_l:cmp r0, r1 /* clear loop... */
bhs clbss_e /* if reached end of bss, exit */
str r2, [r0]
add r0, r0, #4
b clbss_l
clbss_e:
#ifndef CONFIG_NAND_SPL
bl coloured_LED_init
bl red_led_on
#endif
#endif
relocate_done:

/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
#ifdef CONFIG_NAND_SPL
ldr pc, _nand_boot

_nand_boot: .word nand_boot
#else
ldr r0, _board_init_r_ofs
adr r1, _start
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:
.word board_init_r - _start
#endif
bx lr

_rel_dyn_start_ofs:
.word __rel_dyn_start - _start
Expand All @@ -399,6 +350,11 @@ _mmu_table_base:
.word mmu_table
#endif

.globl c_runtime_cpu_setup
c_runtime_cpu_setup:

mov pc, lr

#ifndef CONFIG_NAND_SPL
/*
* we assume that cache operation is done before. (eg. cleanup_before_linux())
Expand Down
53 changes: 8 additions & 45 deletions arch/arm/cpu/arm720t/start.S
Expand Up @@ -147,12 +147,7 @@ reset:
bl cpu_init_crit
#endif

/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
ldr r0,=0x00000000
bl board_init_f
bl _main

/*------------------------------------------------------------------------------*/

Expand All @@ -169,14 +164,10 @@ relocate_code:
mov r5, r1 /* save addr of gd */
mov r6, r2 /* save addr of destination */

/* Set up the stack */
stack_setup:
mov sp, r4

adr r0, _start
cmp r0, r6
moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
beq clear_bss /* skip relocation */
beq relocate_done /* skip relocation */
mov r1, r6 /* r1 <- scratch for copy_loop */
ldr r3, _bss_start_ofs
add r2, r0, r3 /* r2 <- source end address */
Expand Down Expand Up @@ -228,50 +219,22 @@ fixnext:
blo fixloop
#endif

clear_bss:
#ifndef CONFIG_SPL_BUILD
ldr r0, _bss_start_ofs
ldr r1, _bss_end_ofs
mov r4, r6 /* reloc addr */
add r0, r0, r4
add r1, r1, r4
mov r2, #0x00000000 /* clear */

clbss_l:cmp r0, r1 /* clear loop... */
bhs clbss_e /* if reached end of bss, exit */
str r2, [r0]
add r0, r0, #4
b clbss_l
clbss_e:

bl coloured_LED_init
bl red_led_on
#endif
relocate_done:

/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
ldr r0, _board_init_r_ofs
adr r1, _start
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:
.word board_init_r - _start

_rel_dyn_start_ofs:
.word __rel_dyn_start - _start
_rel_dyn_end_ofs:
.word __rel_dyn_end - _start
_dynsym_start_ofs:
.word __dynsym_start - _start

.globl c_runtime_cpu_setup
c_runtime_cpu_setup:

mov pc, lr

/*
*************************************************************************
*
Expand Down
61 changes: 8 additions & 53 deletions arch/arm/cpu/arm920t/start.S
Expand Up @@ -182,12 +182,7 @@ copyex:
bl cpu_init_crit
#endif

/* Set stackpointer in internal RAM to call board_init_f */
call_board_init_f:
ldr sp, =(CONFIG_SYS_INIT_SP_ADDR)
bic sp, sp, #7 /* 8-byte alignment for ABI compliance */
ldr r0,=0x00000000
bl board_init_f
bl _main

/*------------------------------------------------------------------------------*/

Expand All @@ -204,14 +199,10 @@ relocate_code:
mov r5, r1 /* save addr of gd */
mov r6, r2 /* save addr of destination */

/* Set up the stack */
stack_setup:
mov sp, r4

adr r0, _start
cmp r0, r6
moveq r9, #0 /* no relocation. relocation offset(r9) = 0 */
beq clear_bss /* skip relocation */
beq relocate_done /* skip relocation */
mov r1, r6 /* r1 <- scratch for copy_loop */
ldr r3, _bss_start_ofs
add r2, r0, r3 /* r2 <- source end address */
Expand Down Expand Up @@ -263,58 +254,22 @@ fixnext:
blo fixloop
#endif

clear_bss:
#ifndef CONFIG_SPL_BUILD
ldr r0, _bss_start_ofs
ldr r1, _bss_end_ofs
mov r4, r6 /* reloc addr */
add r0, r0, r4
add r1, r1, r4
mov r2, #0x00000000 /* clear */

clbss_l:cmp r0, r1 /* clear loop... */
bhs clbss_e /* if reached end of bss, exit */
str r2, [r0]
add r0, r0, #4
b clbss_l
clbss_e:

bl coloured_LED_init
bl red_led_on
#endif

/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
#ifdef CONFIG_NAND_SPL
ldr r0, _nand_boot_ofs
mov pc, r0
relocate_done:

_nand_boot_ofs:
.word nand_boot
#else
ldr r0, _board_init_r_ofs
adr r1, _start
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:
.word board_init_r - _start
#endif

_rel_dyn_start_ofs:
.word __rel_dyn_start - _start
_rel_dyn_end_ofs:
.word __rel_dyn_end - _start
_dynsym_start_ofs:
.word __dynsym_start - _start

.globl c_runtime_cpu_setup
c_runtime_cpu_setup:

mov pc, lr

/*
*************************************************************************
*
Expand Down

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