diff options
Diffstat (limited to 'arch/arm/cpu/arm720t/start.S')
| -rw-r--r-- | arch/arm/cpu/arm720t/start.S | 132 |
1 files changed, 68 insertions, 64 deletions
diff --git a/arch/arm/cpu/arm720t/start.S b/arch/arm/cpu/arm720t/start.S index 8cd267b..f048bad 100644 --- a/arch/arm/cpu/arm720t/start.S +++ b/arch/arm/cpu/arm720t/start.S @@ -81,14 +81,17 @@ _TEXT_BASE: /* * These are defined in the board-specific linker script. + * Subtracting _start from them lets the linker put their + * relative position in the executable instead of leaving + * them null. */ -.globl _bss_start -_bss_start: - .word __bss_start +.globl _bss_start_ofs +_bss_start_ofs: + .word __bss_start - _start -.globl _bss_end -_bss_end: - .word _end +.globl _bss_end_ofs +_bss_end_ofs: + .word _end - _start #ifdef CONFIG_USE_IRQ /* IRQ stack memory (calculated at run-time) */ @@ -107,30 +110,6 @@ FIQ_STACK_START: IRQ_STACK_START_IN: .word 0x0badc0de -.globl _datarel_start -_datarel_start: - .word __datarel_start - -.globl _datarelrolocal_start -_datarelrolocal_start: - .word __datarelrolocal_start - -.globl _datarellocal_start -_datarellocal_start: - .word __datarellocal_start - -.globl _datarelro_start -_datarelro_start: - .word __datarelro_start - -.globl _got_start -_got_start: - .word __got_start - -.globl _got_end -_got_end: - .word __got_end - /* * the actual reset code */ @@ -159,6 +138,7 @@ reset: /* 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 @@ -176,56 +156,73 @@ relocate_code: mov r4, r0 /* save addr_sp */ mov r5, r1 /* save addr of gd */ mov r6, r2 /* save addr of destination */ - mov r7, r2 /* save addr of destination */ /* Set up the stack */ stack_setup: mov sp, r4 adr r0, _start - ldr r2, _TEXT_BASE - ldr r3, _bss_start - sub r2, r3, r2 /* r2 <- size of armboot */ - add r2, r0, r2 /* r2 <- source end address */ cmp r0, r6 - beq clear_bss + beq clear_bss /* skip relocation */ + mov r1, r6 /* r1 <- scratch for copy_loop */ + ldr r2, _TEXT_BASE + ldr r3, _bss_start_ofs + add r2, r0, r3 /* r2 <- source end address */ copy_loop: ldmia r0!, {r9-r10} /* copy from source address [r0] */ - stmia r6!, {r9-r10} /* copy to target address [r1] */ + stmia r1!, {r9-r10} /* copy to target address [r1] */ cmp r0, r2 /* until source end address [r2] */ blo copy_loop #ifndef CONFIG_PRELOADER - /* fix got entries */ - ldr r1, _TEXT_BASE /* Text base */ - mov r0, r7 /* reloc addr */ - ldr r2, _got_start /* addr in Flash */ - ldr r3, _got_end /* addr in Flash */ - sub r3, r3, r1 - add r3, r3, r0 - sub r2, r2, r1 - add r2, r2, r0 - + /* + * fix .rel.dyn relocations + */ + ldr r0, _TEXT_BASE /* r0 <- Text base */ + sub r9, r6, r0 /* r9 <- relocation offset */ + ldr r10, _dynsym_start_ofs /* r10 <- sym table ofs */ + add r10, r10, r0 /* r10 <- sym table in FLASH */ + ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start ofs */ + add r2, r2, r0 /* r2 <- rel dyn start in FLASH */ + ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end ofs */ + add r3, r3, r0 /* r3 <- rel dyn end in FLASH */ fixloop: - ldr r4, [r2] - sub r4, r4, r1 - add r4, r4, r0 - str r4, [r2] - add r2, r2, #4 + ldr r0, [r2] /* r0 <- location to fix up, IN FLASH! */ + add r0, r0, r9 /* r0 <- location to fix up in RAM */ + ldr r1, [r2, #4] + and r7, r1, #0xff + cmp r7, #23 /* relative fixup? */ + beq fixrel + cmp r7, #2 /* absolute fixup? */ + beq fixabs + /* ignore unknown type of fixup */ + b fixnext +fixabs: + /* absolute fix: set location to (offset) symbol value */ + mov r1, r1, LSR #4 /* r1 <- symbol index in .dynsym */ + add r1, r10, r1 /* r1 <- address of symbol in table */ + ldr r1, [r1, #4] /* r1 <- symbol value */ + add r1, r9 /* r1 <- relocated sym addr */ + b fixnext +fixrel: + /* relative fix: increase location by offset */ + ldr r1, [r0] + add r1, r1, r9 +fixnext: + str r1, [r0] + add r2, r2, #8 /* each rel.dyn entry is 8 bytes */ cmp r2, r3 blo fixloop #endif clear_bss: #ifndef CONFIG_PRELOADER - ldr r0, _bss_start - ldr r1, _bss_end + ldr r0, _bss_start_ofs + ldr r1, _bss_end_ofs ldr r3, _TEXT_BASE /* Text base */ - mov r4, r7 /* reloc addr */ - sub r0, r0, r3 + mov r4, r6 /* reloc addr */ add r0, r0, r4 - sub r1, r1, r3 add r1, r1, r4 mov r2, #0x00000000 /* clear */ @@ -242,18 +239,25 @@ clbss_l:str r2, [r0] /* clear loop... */ * We are done. Do not return, instead branch to second part of board * initialization, now running from RAM. */ - ldr r0, _TEXT_BASE - ldr r2, _board_init_r - sub r2, r2, r0 - add r2, r2, r7 /* position from board_init_r in 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, r7 /* dest_addr */ + mov r1, r6 /* dest_addr */ /* jump to it ... */ - mov lr, r2 mov pc, lr -_board_init_r: .word board_init_r +_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 /* ************************************************************************* |