[U-Boot] [PATCH 17/26 v2][NEXT] ARM: implement relocation for ARM925
Heiko Schocher
hs at denx.de
Fri Sep 17 13:10:44 CEST 2010
Change the implementation for arm925 to relocate the code to
an arbitrary address in RAM.
Portions of this work were supported by funding from
the CE Linux Forum.
Signed-off-by: Heiko Schocher <hs at denx.de>
---
arch/arm/cpu/arm925t/start.S | 204 ++++++++++++++++++++++++++++++++++++++-
arch/arm/cpu/arm925t/u-boot.lds | 14 +++-
2 files changed, 216 insertions(+), 2 deletions(-)
diff --git a/arch/arm/cpu/arm925t/start.S b/arch/arm/cpu/arm925t/start.S
index 346615e..c0a856d 100644
--- a/arch/arm/cpu/arm925t/start.S
+++ b/arch/arm/cpu/arm925t/start.S
@@ -81,12 +81,15 @@ _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.
@@ -111,7 +114,198 @@ 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
+
+ /*
+ * Set up 925T mode
+ */
+ mov r1, #0x81 /* Set ARM925T configuration. */
+ mcr p15, 0, r1, c15, c1, 0 /* Write ARM925T configuration register. */
+
+ /*
+ * turn off the watchdog, unlock/diable sequence
+ */
+ mov r1, #0xF5
+ ldr r0, =WDTIM_MODE
+ strh r1, [r0]
+ mov r1, #0xA0
+ strh r1, [r0]
+
+ /*
+ * mask all IRQs by setting all bits in the INTMR - default
+ */
+ mov r1, #0xffffffff
+ ldr r0, =REG_IHL1_MIR
+ str r1, [r0]
+ ldr r0, =REG_IHL2_MIR
+ str r1, [r0]
+
+ /*
+ * wait for dpll to lock
+ */
+ ldr r0, =CK_DPLL1
+ mov r1, #0x10
+ strh r1, [r0]
+poll1:
+ ldrh r1, [r0]
+ ands r1, r1, #0x01
+ beq poll1
+
+ /*
+ * we do sys-critical inits only at reboot,
+ * not when booting from ram!
+ */
+#ifndef CONFIG_SKIP_LOWLEVEL_INIT
+ bl cpu_init_crit
+#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
+#endif
+
+/*
+ * We are done. Do not return, instead branch to second part of board
+ * initialization, now running from RAM.
+ */
+#ifdef CONFIG_NAND_SPL
+ ldr pc, _nand_boot
+
+_nand_boot: .word nand_boot
+#else
+ 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
+#endif
+
+#else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/*
* the actual reset code
*/
@@ -211,7 +405,7 @@ clbss_l:str r2, [r0] /* clear loop... */
ldr pc, _start_armboot
_start_armboot: .word start_armboot
-
+#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
/*
*************************************************************************
@@ -295,9 +489,13 @@ cpu_init_crit:
sub sp, sp, #S_FRAME_SIZE @ carve out a frame on current user stack
stmia sp, {r0 - r12} @ Save user registers (now in svc mode) r0-r12
+#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 - r3} @ get values for "aborted" pc and cpsr (into parm regs)
add r0, sp, #S_FRAME_SIZE @ grab pointer to old stack
@@ -328,9 +526,13 @@ cpu_init_crit:
.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
+#endif
str lr, [r13] @ save caller lr in position 0 of saved stack
mrs lr, spsr @ get the spsr
diff --git a/arch/arm/cpu/arm925t/u-boot.lds b/arch/arm/cpu/arm925t/u-boot.lds
index e21d6dc..1c4e9bc 100644
--- a/arch/arm/cpu/arm925t/u-boot.lds
+++ b/arch/arm/cpu/arm925t/u-boot.lds
@@ -42,11 +42,23 @@ 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
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