[U-Boot] [PATCH 22/26] ARM: implement relocation for s3c44b0
Heiko Schocher
hs at denx.de
Wed Aug 11 20:16:34 CEST 2010
Change the implementation for s3c44b0 to relocate the code to
an arbitrary address in RAM.
Signed-off-by: Heiko Schocher <hs at denx.de>
---
arch/arm/cpu/s3c44b0/start.S | 174 +++++++++++++++++++++++++++++++++++++++
arch/arm/cpu/s3c44b0/u-boot.lds | 14 +++-
2 files changed, 187 insertions(+), 1 deletions(-)
diff --git a/arch/arm/cpu/s3c44b0/start.S b/arch/arm/cpu/s3c44b0/start.S
index 0063063..e1ab5cc 100644
--- a/arch/arm/cpu/s3c44b0/start.S
+++ b/arch/arm/cpu/s3c44b0/start.S
@@ -63,12 +63,15 @@ _start: b reset
*************************************************************************
*/
+.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.
@@ -93,7 +96,177 @@ 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
+ /*
+ * before relocating, we have to setup RAM timing
+ * because memory timing is board-dependend, you will
+ * find a lowlevel_init.S in your board directory.
+ */
+ 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
+/*
+ now copy to sram the interrupt vector
+*/
+ adr r0, real_vectors
+ add r2, r0, #1024
+ ldr r1, =0x0c000000
+ add r1, r1, #0x08
+vector_copy_loop:
+ ldmia r0!, {r3-r10}
+ stmia r1!, {r3-r10}
+ cmp r0, r2
+ ble vector_copy_loop
+#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
*/
@@ -169,6 +342,7 @@ stack_setup:
_start_armboot: .word start_armboot
+#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/*
*************************************************************************
diff --git a/arch/arm/cpu/s3c44b0/u-boot.lds b/arch/arm/cpu/s3c44b0/u-boot.lds
index 267d94c..bbc8c3a 100644
--- a/arch/arm/cpu/s3c44b0/u-boot.lds
+++ b/arch/arm/cpu/s3c44b0/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) }
--
1.6.2.5
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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