MIPS: use asm.h macros in mips32 start.S

Where the mips32 & mips64 implementations of start.S differ in terms of
access sizes & offsets, use the appropriate macros from asm.h to
abstract those differences away. This is in preparation for sharing a
single copy of start.S between mips32 & mips64.

The exception to this is loads of immediates to be written to the cop0
Config register, which is a 32bit register on mips64 and therefore
constants written to it can be loaded as such.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
This commit is contained in:
Paul Burton 2015-01-29 10:04:08 +00:00 committed by Daniel Schwierzeck
parent d4d774e00e
commit a39b1cb7f0

View File

@ -8,6 +8,7 @@
#include <asm-offsets.h>
#include <config.h>
#include <asm/asm.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
@ -98,8 +99,8 @@ _start:
reset:
/* Clear watch registers */
mtc0 zero, CP0_WATCHLO
mtc0 zero, CP0_WATCHHI
MTC0 zero, CP0_WATCHLO
MTC0 zero, CP0_WATCHHI
/* WP(Watch Pending), SW0/1 should be cleared */
mtc0 zero, CP0_CAUSE
@ -116,21 +117,26 @@ reset:
mtc0 t0, CP0_CONFIG
#endif
/* Initialize $gp */
/*
* Initialize $gp, force pointer sized alignment of bal instruction to
* forbid the compiler to put nop's between bal and _gp. This is
* required to keep _gp and ra aligned to 8 byte.
*/
.align PTRLOG
bal 1f
nop
.word _gp
PTR _gp
1:
lw gp, 0(ra)
PTR_L gp, 0(ra)
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/* Initialize any external memory */
la t9, lowlevel_init
PTR_LA t9, lowlevel_init
jalr t9
nop
/* Initialize caches... */
la t9, mips_cache_reset
PTR_LA t9, mips_cache_reset
jalr t9
nop
@ -140,15 +146,15 @@ reset:
#endif
/* Set up temporary stack */
li t0, -16
li t1, CONFIG_SYS_INIT_SP_ADDR
PTR_LI t0, -16
PTR_LI t1, CONFIG_SYS_INIT_SP_ADDR
and sp, t1, t0 # force 16 byte alignment
sub sp, sp, GD_SIZE # reserve space for gd
PTR_SUB sp, sp, GD_SIZE # reserve space for gd
and sp, sp, t0 # force 16 byte alignment
move k0, sp # save gd pointer
#ifdef CONFIG_SYS_MALLOC_F_LEN
li t2, CONFIG_SYS_MALLOC_F_LEN
sub sp, sp, t2 # reserve space for early malloc
PTR_LI t2, CONFIG_SYS_MALLOC_F_LEN
PTR_SUB sp, sp, t2 # reserve space for early malloc
and sp, sp, t0 # force 16 byte alignment
#endif
move fp, sp
@ -158,14 +164,14 @@ reset:
1:
sw zero, 0(t0)
blt t0, t1, 1b
addi t0, 4
PTR_ADDI t0, 4
#ifdef CONFIG_SYS_MALLOC_F_LEN
addu t0, k0, GD_MALLOC_BASE # gd->malloc_base offset
PTR_ADDU t0, k0, GD_MALLOC_BASE # gd->malloc_base offset
sw sp, 0(t0)
#endif
la t9, board_init_f
PTR_LA t9, board_init_f
jr t9
move ra, zero
@ -188,14 +194,14 @@ relocate_code:
move s0, a1 # save gd in s0
move s2, a2 # save destination address in s2
li t0, CONFIG_SYS_MONITOR_BASE
sub s1, s2, t0 # s1 <-- relocation offset
PTR_LI t0, CONFIG_SYS_MONITOR_BASE
PTR_SUB s1, s2, t0 # s1 <-- relocation offset
la t3, in_ram
lw t2, -12(t3) # t2 <-- __image_copy_end
PTR_LA t3, in_ram
PTR_L t2, -(3 * PTRSIZE)(t3) # t2 <-- __image_copy_end
move t1, a2
add gp, s1 # adjust gp
PTR_ADD gp, s1 # adjust gp
/*
* t0 = source address
@ -205,26 +211,26 @@ relocate_code:
1:
lw t3, 0(t0)
sw t3, 0(t1)
addu t0, 4
PTR_ADDU t0, 4
blt t0, t2, 1b
addu t1, 4
PTR_ADDU t1, 4
/* If caches were enabled, we would have to flush them here. */
sub a1, t1, s2 # a1 <-- size
la t9, flush_cache
PTR_SUB a1, t1, s2 # a1 <-- size
PTR_LA t9, flush_cache
jalr t9
move a0, s2 # a0 <-- destination address
/* Jump to where we've relocated ourselves */
addi t0, s2, in_ram - _start
PTR_ADDI t0, s2, in_ram - _start
jr t0
nop
.word __rel_dyn_end
.word __rel_dyn_start
.word __image_copy_end
.word _GLOBAL_OFFSET_TABLE_
.word num_got_entries
PTR __rel_dyn_end
PTR __rel_dyn_start
PTR __image_copy_end
PTR _GLOBAL_OFFSET_TABLE_
PTR num_got_entries
in_ram:
/*
@ -233,46 +239,46 @@ in_ram:
* GOT[0] is reserved. GOT[1] is also reserved for the dynamic object
* generated by GNU ld. Skip these reserved entries from relocation.
*/
lw t3, -4(t0) # t3 <-- num_got_entries
lw t8, -8(t0) # t8 <-- _GLOBAL_OFFSET_TABLE_
add t8, s1 # t8 now holds relocated _G_O_T_
addi t8, t8, 8 # skipping first two entries
li t2, 2
PTR_L t3, -(1 * PTRSIZE)(t0) # t3 <-- num_got_entries
PTR_L t8, -(2 * PTRSIZE)(t0) # t8 <-- _GLOBAL_OFFSET_TABLE_
PTR_ADD t8, s1 # t8 now holds relocated _G_O_T_
PTR_ADDI t8, t8, 2 * PTRSIZE # skipping first two entries
PTR_LI t2, 2
1:
lw t1, 0(t8)
PTR_L t1, 0(t8)
beqz t1, 2f
add t1, s1
sw t1, 0(t8)
PTR_ADD t1, s1
PTR_S t1, 0(t8)
2:
addi t2, 1
PTR_ADDI t2, 1
blt t2, t3, 1b
addi t8, 4
PTR_ADDI t8, PTRSIZE
/* Update dynamic relocations */
lw t1, -16(t0) # t1 <-- __rel_dyn_start
lw t2, -20(t0) # t2 <-- __rel_dyn_end
PTR_L t1, -(4 * PTRSIZE)(t0) # t1 <-- __rel_dyn_start
PTR_L t2, -(5 * PTRSIZE)(t0) # t2 <-- __rel_dyn_end
b 2f # skip first reserved entry
addi t1, 8
PTR_ADDI t1, 2 * PTRSIZE
1:
lw t8, -4(t1) # t8 <-- relocation info
li t3, 3
PTR_LI t3, 3
bne t8, t3, 2f # skip non R_MIPS_REL32 entries
nop
lw t3, -8(t1) # t3 <-- location to fix up in FLASH
PTR_L t3, -(2 * PTRSIZE)(t1) # t3 <-- location to fix up in FLASH
lw t8, 0(t3) # t8 <-- original pointer
add t8, s1 # t8 <-- adjusted pointer
PTR_L t8, 0(t3) # t8 <-- original pointer
PTR_ADD t8, s1 # t8 <-- adjusted pointer
add t3, s1 # t3 <-- location to fix up in RAM
sw t8, 0(t3)
PTR_ADD t3, s1 # t3 <-- location to fix up in RAM
PTR_S t8, 0(t3)
2:
blt t1, t2, 1b
addi t1, 8 # each rel.dyn entry is 8 bytes
PTR_ADDI t1, 2 * PTRSIZE # each rel.dyn entry is 2*PTRSIZE bytes
/*
* Clear BSS
@ -280,17 +286,17 @@ in_ram:
* GOT is now relocated. Thus __bss_start and __bss_end can be
* accessed directly via $gp.
*/
la t1, __bss_start # t1 <-- __bss_start
la t2, __bss_end # t2 <-- __bss_end
PTR_LA t1, __bss_start # t1 <-- __bss_start
PTR_LA t2, __bss_end # t2 <-- __bss_end
1:
sw zero, 0(t1)
PTR_S zero, 0(t1)
blt t1, t2, 1b
addi t1, 4
PTR_ADDI t1, PTRSIZE
move a0, s0 # a0 <-- gd
move a1, s2
la t9, board_init_r
PTR_LA t9, board_init_r
jr t9
move ra, zero