[U-Boot] [PATCH 20/26] ARM: implement relocation for ixp

Heiko Schocher hs at denx.de
Wed Aug 11 20:16:29 CEST 2010


Change the implementation for ixp to relocate the code to
an arbitrary address in RAM.

Signed-off-by: Heiko Schocher <hs at denx.de>
---
 arch/arm/cpu/ixp/start.S    |  280 +++++++++++++++++++++++++++++++++++++++++++
 arch/arm/cpu/ixp/u-boot.lds |   14 ++-
 2 files changed, 293 insertions(+), 1 deletions(-)

diff --git a/arch/arm/cpu/ixp/start.S b/arch/arm/cpu/ixp/start.S
index 6efe333..b2c8255 100644
--- a/arch/arm/cpu/ixp/start.S
+++ b/arch/arm/cpu/ixp/start.S
@@ -93,12 +93,15 @@ _fiq:			.word fiq
  * - jump to second stage
  */

+.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.
@@ -123,6 +126,274 @@ 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:
+	/* disable mmu, set big-endian */
+	mov	r0, #0xf8
+	mcr	p15, 0, r0, c1, c0, 0
+	CPWAIT  r0
+
+	/* invalidate I & D caches & BTB */
+	mcr	p15, 0, r0, c7, c7, 0
+	CPWAIT	r0
+
+	/* invalidate I & Data TLB */
+	mcr	p15, 0, r0, c8, c7, 0
+	CPWAIT r0
+
+	/* drain write and fill buffers */
+	mcr	p15, 0, r0, c7, c10, 4
+	CPWAIT	r0
+
+	/* disable write buffer coalescing */
+	mrc	p15, 0, r0, c1, c0, 1
+	orr	r0, r0, #1
+	mcr	p15, 0, r0, c1, c0, 1
+	CPWAIT	r0
+
+	/* set EXP CS0 to the optimum timing */
+	ldr	r1, =CONFIG_SYS_EXP_CS0
+	ldr     r2, =IXP425_EXP_CS0
+	str     r1, [r2]
+
+	/* make sure flash is visible at 0 */
+#if 0
+	ldr	r2, =IXP425_EXP_CFG0
+	ldr     r1, [r2]
+	orr     r1, r1, #0x80000000
+	str     r1, [r2]
+#endif
+	mov	r1, #CONFIG_SYS_SDR_CONFIG
+	ldr     r2, =IXP425_SDR_CONFIG
+	str     r1, [r2]
+
+	/* disable refresh cycles */
+	mov	r1, #0
+	ldr     r3, =IXP425_SDR_REFRESH
+	str	r1, [r3]
+
+	/* send nop command */
+	mov	r1, #3
+	ldr	r4, =IXP425_SDR_IR
+	str	r1, [r4]
+	DELAY_FOR 0x4000, r0
+
+	/* set SDRAM internal refresh val */
+	ldr	r1, =CONFIG_SYS_SDRAM_REFRESH_CNT
+	str     r1, [r3]
+	DELAY_FOR 0x4000, r0
+
+	/* send precharge-all command to close all open banks */
+	mov     r1, #2
+	str     r1, [r4]
+	DELAY_FOR 0x4000, r0
+
+	/* provide 8 auto-refresh cycles */
+	mov     r1, #4
+	mov     r5, #8
+111:    str	r1, [r4]
+	DELAY_FOR 0x100, r0
+	subs	r5, r5, #1
+	bne	111b
+
+	/* set mode register in sdram */
+	mov	r1, #CONFIG_SYS_SDR_MODE_CONFIG
+	str	r1, [r4]
+	DELAY_FOR 0x4000, r0
+
+	/* send normal operation command */
+	mov	r1, #6
+	str	r1, [r4]
+	DELAY_FOR 0x4000, r0
+
+	/* copy */
+	mov     r0, #0
+	mov     r4, r0
+	add     r2, r0, #CONFIG_SYS_MONITOR_LEN
+	mov     r1, #0x10000000
+	mov     r5, r1
+
+    30:
+	ldr     r3, [r0], #4
+	str     r3, [r1], #4
+	cmp     r0, r2
+	bne     30b
+
+	/* invalidate I & D caches & BTB */
+	mcr	p15, 0, r0, c7, c7, 0
+	CPWAIT	r0
+
+	/* invalidate I & Data TLB */
+	mcr	p15, 0, r0, c8, c7, 0
+	CPWAIT r0
+
+	/* drain write and fill buffers */
+	mcr	p15, 0, r0, c7, c10, 4
+	CPWAIT	r0
+
+	/* move flash to 0x50000000 */
+	ldr	r2, =IXP425_EXP_CFG0
+	ldr     r1, [r2]
+	bic     r1, r1, #0x80000000
+	str     r1, [r2]
+
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+
+	/* invalidate I & Data TLB */
+	mcr	p15, 0, r0, c8, c7, 0
+	CPWAIT r0
+
+	/* enable I cache */
+	mrc     p15, 0, r0, c1, c0, 0
+	orr     r0, r0, #MMU_Control_I
+	mcr     p15, 0, r0, c1, c0, 0
+	CPWAIT  r0
+
+	mrs	r0,cpsr			/* set the cpu to SVC32 mode	    */
+	bic	r0,r0,#0x1f		/* (superviser mode, M=10011)	    */
+	orr	r0,r0,#0x13
+	msr	cpsr,r0
+
+/* 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						    */
@@ -304,6 +575,7 @@ clbss_l:str	r2, [r0]		/* clear loop...                    */
 	ldr	pc, _start_armboot

 _start_armboot: .word start_armboot
+#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */


 /****************************************************************************/
@@ -345,9 +617,13 @@ _start_armboot: .word start_armboot
 	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	    */

@@ -382,9 +658,13 @@ _start_armboot: .word start_armboot
 	.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/ixp/u-boot.lds b/arch/arm/cpu/ixp/u-boot.lds
index b8ff2ee..f3d9dc5 100644
--- a/arch/arm/cpu/ixp/u-boot.lds
+++ b/arch/arm/cpu/ixp/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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