ARM: implement relocation for sa1100

Change the implementation for sa1100 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@denx.de>

diff --git a/arch/arm/cpu/sa1100/start.S b/arch/arm/cpu/sa1100/start.S
index deb4745..4730e5a 100644 (file)
--- a/arch/arm/cpu/sa1100/start.S
+++ b/arch/arm/cpu/sa1100/start.S
@@ -73,12 +73,15 @@ _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.
@@ -103,6 +106,156 @@ 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
+#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.
+ */
+       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 +322,7 @@ clbss_l:str r2, [r0]                /* clear loop...                    */
 
 _start_armboot:        .word start_armboot
 
+#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 
 /*
  *************************************************************************
@@ -288,9 +442,13 @@ cpu_init_crit:
        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
 
@@ -321,9 +479,13 @@ 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         @ setup our mode stack
+#endif
 
        str     lr, [r13]                       @ save caller lr / spsr
        mrs     lr, spsr

diff --git a/arch/arm/cpu/sa1100/u-boot.lds b/arch/arm/cpu/sa1100/u-boot.lds
index f6197ac..2e29291 100644 (file)
--- a/arch/arm/cpu/sa1100/u-boot.lds
+++ b/arch/arm/cpu/sa1100/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) }