Change the implementation for arm720t to relocate the code to an arbitrary address in RAM.
Signed-off-by: Heiko Schocher hs@denx.de --- arch/arm/cpu/arm720t/start.S | 170 +++++++++++++++++++++++++++++++++++++++ arch/arm/cpu/arm720t/u-boot.lds | 14 +++- 2 files changed, 183 insertions(+), 1 deletions(-)
diff --git a/arch/arm/cpu/arm720t/start.S b/arch/arm/cpu/arm720t/start.S index d6f2c16..0f5f6c4 100644 --- a/arch/arm/cpu/arm720t/start.S +++ b/arch/arm/cpu/arm720t/start.S @@ -75,12 +75,15 @@ _fiq: .word fiq ************************************************************************* */
+.globl _TEXT_BASE _TEXT_BASE: .word TEXT_BASE
+#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC) .globl _armboot_start _armboot_start: .word _start +#endif
/* * These are defined in the board-specific linker script. @@ -105,6 +108,163 @@ FIQ_STACK_START: .word 0x0badc0de #endif
+#if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) +/* IRQ stack memory (calculated at run-time) + 8 bytes */ +.globl IRQ_STACK_START_IN +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 + */ + +reset: + /* + * set the cpu to SVC32 mode + */ + mrs r0,cpsr + bic r0,r0,#0x1f + orr r0,r0,#0xd3 + msr cpsr,r0 + + /* + * we do sys-critical inits only at reboot, + * not when booting from ram! + */ +#ifndef CONFIG_SKIP_LOWLEVEL_INIT + bl cpu_init_crit +#endif + +#ifdef CONFIG_LPC2292 + bl lowlevel_init +#endif + +/* Set stackpointer in internal RAM to call board_init_f */ +call_board_init_f: + ldr sp, =(CONFIG_SYS_INIT_SP_ADDR) + ldr r0,=0x00000000 + bl board_init_f + +/*------------------------------------------------------------------------------*/ + +/* + * void relocate_code (addr_sp, gd, addr_moni) + * + * This "function" does not return, instead it continues in RAM + * after relocating the monitor code. + * + */ + .globl relocate_code +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 + +#ifndef CONFIG_SKIP_RELOCATE_UBOOT +copy_loop: + ldmia r0!, {r9-r10} /* copy from source address [r0] */ + stmia r6!, {r9-r10} /* copy to target address [r1] */ + cmp r0, r2 /* until source end addreee [r2] */ + ble 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 + +fixloop: + ldr r4, [r2] + sub r4, r4, r1 + add r4, r4, r0 + str r4, [r2] + add r2, r2, #4 + cmp r2, r3 + bne fixloop +#endif +#endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */ + +clear_bss: +#ifndef CONFIG_PRELOADER + ldr r0, _bss_start + ldr r1, _bss_end + 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 */ + +clbss_l:str r2, [r0] /* clear loop... */ + add r0, r0, #4 + cmp r0, r1 + bne clbss_l + + 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. + */ + ldr r0, _TEXT_BASE + ldr r2, _board_init_r + sub r2, r2, r0 + add r2, r2, r7 /* position from board_init_r in RAM */ + /* setup parameters for board_init_r */ + mov r0, r5 /* gd_t */ + mov r1, r7 /* dest_addr */ + /* jump to it ... */ + mov lr, r2 + mov pc, lr + +_board_init_r: .word board_init_r + +#else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/* * the actual reset code @@ -188,6 +348,8 @@ clbss_l:str r2, [r0] /* clear loop... */
_start_armboot: .word start_armboot
+#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */ + /* ************************************************************************* * @@ -444,9 +606,13 @@ lock_loop: stmia sp, {r0 - r12} @ Calling r0-r12 add r8, sp, #S_PC
+#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC) ldr r2, _armboot_start sub r2, r2, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN) sub r2, r2, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ set base 2 words into abort stack +#else + ldr r2, IRQ_STACK_START_IN +#endif ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
@@ -477,9 +643,13 @@ lock_loop: .endm
.macro get_bad_stack +#if defined(CONFIG_SYS_ARM_WITHOUT_RELOC) ldr r13, _armboot_start @ setup our mode stack sub r13, r13, #(CONFIG_STACKSIZE+CONFIG_SYS_MALLOC_LEN) sub r13, r13, #(CONFIG_SYS_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack +#else + ldr r13, IRQ_STACK_START_IN @ setup our mode stack +#endif
str lr, [r13] @ save caller lr / spsr mrs lr, spsr diff --git a/arch/arm/cpu/arm720t/u-boot.lds b/arch/arm/cpu/arm720t/u-boot.lds index c975fc3..4a0bc70 100644 --- a/arch/arm/cpu/arm720t/u-boot.lds +++ b/arch/arm/cpu/arm720t/u-boot.lds @@ -39,11 +39,23 @@ SECTIONS .rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) }
. = ALIGN(4); - .data : { *(.data) } + .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) }