PXA: Implement ELF relocation

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

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

diff --git a/arch/arm/cpu/pxa/start.S b/arch/arm/cpu/pxa/start.S
index 684e44e8389508c1fd27c461afe064f2bb27f882..96bfb5484195d81d2f1372b7eba610c4307ba41a 100644 (file)
--- a/arch/arm/cpu/pxa/start.S
+++ b/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
-_bss_start:
-       .word __bss_start
+.globl _bss_start_ofs
+_bss_start_ofs:
+       .word __bss_start - _start
 
-.globl _bss_end
-_bss_end:
-       .word _end
+.globl _bss_end_ofs
+_bss_end_ofs:
+       .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
-       sub     r2, r3, r2              /* r2 <- size of armboot            */
-       add     r2, r0, r2              /* r2 <- source end address         */
+       ldr     r3, _bss_start_ofs
+       add     r2, r0, r3              /* 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 */
-       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
-
+       /*
+        * fix .rel.dyn relocations
+        */
+       ldr     r0, _TEXT_BASE          /* r0 <- Text base */
+       sub     r9, r7, r0              /* r9 <- relocation offset */
+       ldr     r10, _dynsym_start_ofs  /* r10 <- sym table ofs */
+       add     r10, r10, r0            /* r10 <- sym table in FLASH */
+       ldr     r2, _rel_dyn_start_ofs  /* r2 <- rel dyn start ofs */
+       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]
-       sub     r4, r4, r1
-       add     r4, r4, r0
-       str     r4, [r2]
-       add     r2, r2, #4
+       ldr     r0, [r2]        /* r0 <- location to fix up, IN FLASH! */
+       add     r0, r9          /* r0 <- location to fix up in RAM */
+       ldr     r1, [r2, #4]
+       and     r8, r1, #0xff
+       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     r1, _bss_end
+       ldr     r0, _bss_start_ofs
+       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     r2, _board_init_r
-       sub     r2, r2, r0
-       add     r2, r2, r7      /* position from board_init_r in RAM */
+       ldr     r0, _board_init_r_ofs
+       adr     r1, _start
+       add     r0, r0, r1
+       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) */
 
 /****************************************************************************/

diff --git a/arch/arm/cpu/pxa/u-boot.lds b/arch/arm/cpu/pxa/u-boot.lds
index 74a4c6e90c984c8f312c47afffa4cf1e459718da..d6643f9529b2f95473a2dca4643f00dbfa04c66b 100644 (file)
--- a/arch/arm/cpu/pxa/u-boot.lds
+++ b/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) }