PXA: Implement ELF relocation

Based on patch by: Albert Aribaud <albert.aribaud@free.fr>

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>

arch/arm/cpu/pxa/start.S

@@ -8,6 +8,7 @@
  *  Copyright (C) 2002	Kyle Harris <kharris@nexus-tech.net>
  *  Copyright (C) 2003	Robert Schwebel <r.schwebel@pengutronix.de>
  *  Copyright (C) 2003	Kai-Uwe Bloem <kai-uwe.bloem@auerswald.de>
+ *  Copyright (c) 2010	Marek Vasut <marek.vasut@gmail.com>
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -94,20 +95,16 @@ _fiq:			.word fiq
 _TEXT_BASE:
 	.word	CONFIG_SYS_TEXT_BASE
 
-.globl _armboot_start
-_armboot_start:
-	.word _start
-
 /*
  * These are defined in the board-specific linker script.
  */
-.globl _bss_start
+.globl _bss_start_ofs
-_bss_start:
+_bss_start_ofs:
-	.word __bss_start
+	.word __bss_start - _start
 
-.globl _bss_end
+.globl _bss_end_ofs
-_bss_end:
+_bss_end_ofs:
-	.word _end
+	.word _end - _start
 
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
@@ -127,30 +124,6 @@ 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 reset code
  */
@@ -272,9 +245,8 @@ stack_setup:
 
 	adr	r0, _start
 	ldr	r2, _TEXT_BASE
-	ldr	r3, _bss_start
+	ldr	r3, _bss_start_ofs
-	sub	r2, r3, r2		/* r2 <- size of armboot	    */
+	add	r2, r0, r3		/* r2 <- source end address	    */
-	add	r2, r0, r2		/* r2 <- source end address	    */
 	cmp	r0, r6
 	beq	clear_bss
 
@@ -288,36 +260,54 @@ copy_loop:
 	ldmfd sp!, {r0-r12}
 
 #ifndef CONFIG_PRELOADER
-	/* fix got entries */
+	/*
-	ldr	r1, _TEXT_BASE		/* Text base */
+	 * fix .rel.dyn relocations
-	mov	r0, r7			/* reloc addr */
+	 */
-	ldr	r2, _got_start		/* addr in Flash */
+	ldr	r0, _TEXT_BASE		/* r0 <- Text base */
-	ldr	r3, _got_end		/* addr in Flash */
+	sub	r9, r7, r0		/* r9 <- relocation offset */
-	sub	r3, r3, r1
+	ldr	r10, _dynsym_start_ofs	/* r10 <- sym table ofs */
-	add	r3, r3, r0
+	add	r10, r10, r0		/* r10 <- sym table in FLASH */
-	sub	r2, r2, r1
+	ldr	r2, _rel_dyn_start_ofs	/* r2 <- rel dyn start ofs */
-	add	r2, r2, r0
+	add	r2, r2, r0		/* r2 <- rel dyn start in FLASH */
-
+	ldr	r3, _rel_dyn_end_ofs	/* r3 <- rel dyn end ofs */
+	add	r3, r3, r0		/* r3 <- rel dyn end in FLASH */
 fixloop:
-	ldr	r4, [r2]
+	ldr	r0, [r2]	/* r0 <- location to fix up, IN FLASH! */
-	sub	r4, r4, r1
+	add	r0, r9		/* r0 <- location to fix up in RAM */
-	add	r4, r4, r0
+	ldr	r1, [r2, #4]
-	str	r4, [r2]
+	and	r8, r1, #0xff
-	add	r2, r2, #4
+	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 (offset) 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 addr */
+	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
-	bne	fixloop
+	blo	fixloop
 #endif
 #endif	/* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
 
 clear_bss:
 #ifndef CONFIG_PRELOADER
-	ldr	r0, _bss_start
+	ldr	r0, _bss_start_ofs
-	ldr	r1, _bss_end
+	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			    */
 
@@ -332,24 +322,33 @@ clbss_l:str	r2, [r0]		/* clear loop...		    */
  * initialization, now running from RAM.
  */
 #ifdef CONFIG_ONENAND_IPL
-	ldr     pc, _start_oneboot
+	ldr     r0, _start_oneboot_ofs
+	mov	pc, r0
 
-_start_oneboot: .word start_oneboot
+_start_oneboot_ofs
+	: .word start_oneboot
 #else
-	ldr	r0, _TEXT_BASE
+	ldr	r0, _board_init_r_ofs
-	ldr	r2, _board_init_r
+	adr	r1, _start
-	sub	r2, r2, r0
+	add	r0, r0, r1
-	add	r2, r2, r7	/* position from board_init_r in RAM */
+	add	lr, r0, r9
 	/* 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
+_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
+
 #else /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 
 /****************************************************************************/

arch/arm/cpu/pxa/u-boot.lds

@@ -41,21 +41,18 @@ 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) }
+	__rel_dyn_start = .;
+	.rel.dyn : { *(.rel.dyn) }
+	__rel_dyn_end = .;
+
+	__dynsym_start = .;
+	.dynsym : { *(.dynsym) }
+
+	. = ALIGN(4);
 
-	__got_end = .;
 	. = .;
 	__u_boot_cmd_start = .;
 	.u_boot_cmd : { *(.u_boot_cmd) }