This is mostly a copy of arm926ejs relocation and known to _not_ work correctly a.t.m!
Signed-off-by: Andreas Bießmann andreas.devel@googlemail.com --- changes since v1: - adopted linker script as in patch series v3 "arm926ejs: fix linker file for newer ld support" * move rel.dyn and dynsym after bss * overlay bss with rel.dyn - double checked fixup loop in start.S -> there is still an error in relocation fixup loop breaks the boot, the board hangs after "relocation Offset is: 00f80000"
Dear Albert Aribaud, can you please have a look for that?
arch/arm/cpu/arm920t/start.S | 122 ++++++++++++++++++++------------------- arch/arm/cpu/arm920t/u-boot.lds | 37 +++++++----- 2 files changed, 86 insertions(+), 73 deletions(-)
diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S index d4edde7..adaf193 100644 --- a/arch/arm/cpu/arm920t/start.S +++ b/arch/arm/cpu/arm920t/start.S @@ -77,14 +77,17 @@ _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) */ @@ -103,30 +106,6 @@ 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 start code */ @@ -230,9 +209,8 @@ stack_setup:
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 */ + ldr r3, _bss_start_ofs + add r2, r0, r3 /* r2 <- source end address */ cmp r0, r6 beq clear_bss
@@ -243,35 +221,53 @@ copy_loop: 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, r7, r0 /* r9 <- relocation offset */ + ldr r10, _dynsym_start_ofs /* r10 <- sym table offset */ + add r10, r10, r0 /* r10 <- sym table in FLASH */ + ldr r2, _rel_dyn_start_ofs /* r2 <- rel dyn start offset */ + add r2, r2, r0 /* r2 <- rel dyn start in FLASH */ + ldr r3, _rel_dyn_end_ofs /* r3 <- rel dyn end offset */ + 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 r8, r1, #0xff + cmp r8, #23 /* relative fixup? */ + beq fixrel + cmp r8, #2 /* absolute fixup? */ + beq fixabs + /* ignore unknown type of fixup */ + b fixnext +fixabs: + /* absolute fix: set location to (offste) 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 address */ + 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 add r0, r0, r4 - sub r1, r1, r3 add r1, r1, r4 mov r2, #0x00000000 /* clear */
@@ -289,12 +285,14 @@ clbss_l:str r2, [r0] /* clear loop... */ * initialization, now running from RAM. */ #ifdef CONFIG_NAND_SPL - ldr pc, _nand_boot - -_nand_boot: .word nand_boot + ldr r0, _nand_boot_ofs + adr r1, _start + add pc, r0, r1 +_nand_boot_ofs: + .word nand_boot - _start #else ldr r0, _TEXT_BASE - ldr r2, _board_init_r + ldr r2, _board_init_r_ofs sub r2, r2, r0 add r2, r2, r7 /* position from board_init_r in RAM */ /* setup parameters for board_init_r */ @@ -304,9 +302,17 @@ _nand_boot: .word nand_boot mov lr, r2 mov pc, lr
-_board_init_r: .word board_init_r +_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 + /* ************************************************************************* * @@ -317,8 +323,6 @@ _board_init_r: .word board_init_r * ************************************************************************* */ - - #ifndef CONFIG_SKIP_LOWLEVEL_INIT cpu_init_crit: /* diff --git a/arch/arm/cpu/arm920t/u-boot.lds b/arch/arm/cpu/arm920t/u-boot.lds index 6985434..d16e36d 100644 --- a/arch/arm/cpu/arm920t/u-boot.lds +++ b/arch/arm/cpu/arm920t/u-boot.lds @@ -49,28 +49,37 @@ SECTIONS . = ALIGN(4); .data : { *(.data) - __datarel_start = .; - *(.data.rel) - __datarelrolocal_start = .; - *(.data.rel.ro.local) - __datarellocal_start = .; - *(.data.rel.local) - __datarelro_start = .; - *(.data.rel.ro) }
- __got_start = .; . = ALIGN(4); - .got : { *(.got) }
- __got_end = .; . = .; __u_boot_cmd_start = .; .u_boot_cmd : { *(.u_boot_cmd) } __u_boot_cmd_end = .;
. = ALIGN(4); - __bss_start = .; - .bss (NOLOAD) : { *(.bss) . = ALIGN(4); } - _end = .; + .bss (NOLOAD) : { + __bss_start = .; + *(.bss) + . = ALIGN(4); + _end = .; + } + + .rel.dyn __bss_start (OVERLAY) : { + __rel_dyn_start = .; + *(.rel*) + __rel_dyn_end = .; + } + + .dynsym : { + __dynsym_start = .; + *(.dynsym) + } + + /DISCARD/ : { *(.dynstr*) } + /DISCARD/ : { *(.dynamic*) } + /DISCARD/ : { *(.plt*) } + /DISCARD/ : { *(.interp*) } + /DISCARD/ : { *(.gnu*) } }