diff options
Diffstat (limited to 'cpu/mips/start.S')
| -rw-r--r-- | cpu/mips/start.S | 69 |
1 files changed, 35 insertions, 34 deletions
diff --git a/cpu/mips/start.S b/cpu/mips/start.S index e91e213..c92b162 100644 --- a/cpu/mips/start.S +++ b/cpu/mips/start.S @@ -22,13 +22,11 @@ * MA 02111-1307 USA */ - #include <config.h> #include <version.h> #include <asm/regdef.h> #include <asm/mipsregs.h> - #define RVECENT(f,n) \ b f; nop #define XVECENT(f,bev) \ @@ -192,7 +190,7 @@ _start: .word 0x00000000 .word 0x03e00008 .word 0x00000000 - .word 0x00000000 + .word 0x00000000 /* 0xbfc00428 */ .word 0xdc870000 .word 0xfca70000 @@ -203,7 +201,7 @@ _start: .word 0x00000000 .word 0x03e00008 .word 0x00000000 - .word 0x00000000 + .word 0x00000000 #endif /* CONFIG_PURPLE */ .align 4 reset: @@ -234,34 +232,32 @@ reset: li t0, CONF_CM_UNCACHED mtc0 t0, CP0_CONFIG - /* Initialize GOT pointer. - */ - bal 1f + /* Initialize $gp. + */ + bal 1f nop - .word _GLOBAL_OFFSET_TABLE_ - 1: - move gp, ra - lw t1, 0(ra) - move gp, t1 + .word _gp +1: + lw gp, 0(ra) #ifdef CONFIG_INCA_IP /* Disable INCA-IP Watchdog. */ - la t9, disable_incaip_wdt - jalr t9 + la t9, disable_incaip_wdt + jalr t9 nop #endif /* Initialize any external memory. */ - la t9, lowlevel_init - jalr t9 + la t9, lowlevel_init + jalr t9 nop /* Initialize caches... */ - la t9, mips_cache_reset - jalr t9 + la t9, mips_cache_reset + jalr t9 nop /* ... and enable them. @@ -269,12 +265,11 @@ reset: li t0, CONF_CM_CACHABLE_NONCOHERENT mtc0 t0, CP0_CONFIG - /* Set up temporary stack. */ li a0, CFG_INIT_SP_OFFSET - la t9, mips_cache_lock - jalr t9 + la t9, mips_cache_lock + jalr t9 nop li t0, CFG_SDRAM_BASE + CFG_INIT_SP_OFFSET @@ -284,7 +279,6 @@ reset: j t9 nop - /* * void relocate_code (addr_sp, gd, addr_moni) * @@ -298,7 +292,7 @@ reset: .globl relocate_code .ent relocate_code relocate_code: - move sp, a0 /* Set new stack pointer */ + move sp, a0 /* Set new stack pointer */ li t0, CFG_MONITOR_BASE la t3, in_ram @@ -306,14 +300,14 @@ relocate_code: move t1, a2 /* - * Fix GOT pointer: + * Fix $gp: * - * New GOT-PTR = (old GOT-PTR - CFG_MONITOR_BASE) + Destination Address + * New $gp = (Old $gp - CFG_MONITOR_BASE) + Destination Address */ move t6, gp sub gp, CFG_MONITOR_BASE - add gp, a2 /* gp now adjusted */ - sub t6, gp, t6 /* t6 <-- relocation offset */ + add gp, a2 /* gp now adjusted */ + sub t6, gp, t6 /* t6 <-- relocation offset */ /* * t0 = source address @@ -329,7 +323,7 @@ relocate_code: sw t3, 0(t1) addu t0, 4 ble t0, t2, 1b - addu t1, 4 /* delay slot */ + addu t1, 4 /* delay slot */ #endif /* If caches were enabled, we would have to flush them here. @@ -341,15 +335,22 @@ relocate_code: j t0 nop + .gpword _GLOBAL_OFFSET_TABLE_ /* _GLOBAL_OFFSET_TABLE_ - _gp */ .word uboot_end_data .word uboot_end .word num_got_entries in_ram: - /* Now we want to update GOT. + /* + * Now we want to update GOT. + * + * 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 */ - addi t4, gp, 8 /* Skipping first two entries. */ + lw t4, -16(t0) /* t4 <-- (_GLOBAL_OFFSET_TABLE_ - _gp) */ + add t4, t4, gp /* t4 now holds _GLOBAL_OFFSET_TABLE_ */ + addi t4, t4, 8 /* Skipping first two entries. */ li t2, 2 1: lw t1, 0(t4) @@ -369,7 +370,8 @@ in_ram: add t2, t6 sub t1, 4 -1: addi t1, 4 +1: + addi t1, 4 bltl t1, t2, 1b sw zero, 0(t1) /* delay slot */ @@ -380,11 +382,10 @@ in_ram: .end relocate_code - /* Exception handlers. */ romReserved: - b romReserved + b romReserved romExcHandle: - b romExcHandle + b romExcHandle |