ARM: implement relocation for s3c44b0
authorHeiko Schocher <hs@denx.de>
Fri, 17 Sep 2010 11:10:49 +0000 (13:10 +0200)
committerWolfgang Denk <wd@denx.de>
Sun, 19 Sep 2010 17:29:55 +0000 (19:29 +0200)
Change the implementation for s3c44b0 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>
arch/arm/cpu/s3c44b0/start.S
arch/arm/cpu/s3c44b0/u-boot.lds

index 0063063f45d436914c06c40c71f3766ffff653d6..e1ab5ccb3629ceccad87eada5f7aeff10b6e1923 100644 (file)
@@ -63,12 +63,15 @@ _start:     b       reset
  *************************************************************************
  */
 
+.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.
@@ -93,7 +96,177 @@ 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
+       /*
+        * before relocating, we have to setup RAM timing
+        * because memory timing is board-dependend, you will
+        * find a lowlevel_init.S in your board directory.
+        */
+       bl      lowlevel_init
+#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
+/*
+       now copy to sram the interrupt vector
+*/
+       adr     r0, real_vectors
+       add     r2, r0, #1024
+       ldr     r1, =0x0c000000
+       add     r1, r1, #0x08
+vector_copy_loop:
+       ldmia   r0!, {r3-r10}
+       stmia   r1!, {r3-r10}
+       cmp     r0, r2
+       ble     vector_copy_loop
+#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
  */
@@ -169,6 +342,7 @@ stack_setup:
 
 _start_armboot:        .word start_armboot
 
+#endif /* #if !defined(CONFIG_SYS_ARM_WITHOUT_RELOC) */
 
 /*
  *************************************************************************
index 267d94c083d6d3d72b5481801c1782e1f6d542b9..bbc8c3aa552e0887028293322bb249a315c3c661 100644 (file)
@@ -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) }