armv7: start.S: fixes and enhancements for SPL

- Allow SPL to have .bss disjoint from rest of the image
- Allow for .bss setup in CONFIG_SPL_BUILD case too.
- Take care of the special case where relocation offset = 0.
- Compile out exception handling code and install a simpler
  vector

Signed-off-by: Aneesh V <aneesh@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 5c87e9c333574bdfb4098ade35715d77f646043a..02a25354e926a15dd5ed453d91174b03dae29cbf 100644 (file)
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -42,7 +42,16 @@ _start: b    reset
        ldr     pc, _not_used
        ldr     pc, _irq
        ldr     pc, _fiq
-
+#ifdef CONFIG_SPL_BUILD
+_undefined_instruction: .word _undefined_instruction
+_software_interrupt:   .word _software_interrupt
+_prefetch_abort:       .word _prefetch_abort
+_data_abort:           .word _data_abort
+_not_used:             .word _not_used
+_irq:                  .word _irq
+_fiq:                  .word _fiq
+_pad:                  .word 0x12345678 /* now 16*4=64 */
+#else
 _undefined_instruction: .word undefined_instruction
 _software_interrupt:   .word software_interrupt
 _prefetch_abort:       .word prefetch_abort
@@ -51,6 +60,8 @@ _not_used:            .word not_used
 _irq:                  .word irq
 _fiq:                  .word fiq
 _pad:                  .word 0x12345678 /* now 16*4=64 */
+#endif /* CONFIG_SPL_BUILD */
+
 .global _end_vect
 _end_vect:
 
@@ -89,6 +100,10 @@ _armboot_start:
 _bss_start_ofs:
        .word __bss_start - _start
 
+.global        _image_copy_end_ofs
+_image_copy_end_ofs:
+       .word   __image_copy_end - _start
+
 .globl _bss_end_ofs
 _bss_end_ofs:
        .word __bss_end__ - _start
@@ -182,12 +197,11 @@ stack_setup:
        mov     sp, r4
 
        adr     r0, _start
-#ifndef CONFIG_SPL_BUILD
        cmp     r0, r6
+       moveq   r9, #0          /* no relocation. relocation offset(r9) = 0 */
        beq     clear_bss               /* skip relocation */
-#endif
        mov     r1, r6                  /* r1 <- scratch for copy_loop */
-       ldr     r3, _bss_start_ofs
+       ldr     r3, _image_copy_end_ofs
        add     r2, r0, r3              /* r2 <- source end address         */
 
 copy_loop:
@@ -235,20 +249,34 @@ fixnext:
        add     r2, r2, #8              /* each rel.dyn entry is 8 bytes */
        cmp     r2, r3
        blo     fixloop
+       b       clear_bss
+_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
+
+#endif /* #ifndef CONFIG_SPL_BUILD */
 
 clear_bss:
+#ifdef CONFIG_SPL_BUILD
+       /* No relocation for SPL */
+       ldr     r0, =__bss_start
+       ldr     r1, =__bss_end__
+#else
        ldr     r0, _bss_start_ofs
        ldr     r1, _bss_end_ofs
        mov     r4, r6                  /* reloc addr */
        add     r0, r0, r4
        add     r1, r1, r4
+#endif
        mov     r2, #0x00000000         /* clear                            */
 
 clbss_l:str    r2, [r0]                /* clear loop...                    */
        add     r0, r0, #4
        cmp     r0, r1
        bne     clbss_l
-#endif /* #ifndef CONFIG_SPL_BUILD */
 
 /*
  * We are done. Do not return, instead branch to second part of board
@@ -276,12 +304,6 @@ jump_2_ram:
 _board_init_r_ofs:
        .word board_init_r - _start
 
-_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
 
 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
 /*************************************************************************
@@ -329,6 +351,8 @@ cpu_init_crit:
        mov     lr, ip                  @ restore link
        mov     pc, lr                  @ back to my caller
 #endif
+
+#ifndef CONFIG_SPL_BUILD
 /*
  *************************************************************************
  *
@@ -516,4 +540,5 @@ fiq:
        bad_save_user_regs
        bl      do_fiq
 
-#endif
+#endif /* CONFIG_USE_IRQ */
+#endif /* CONFIG_SPL_BUILD */

diff --git a/arch/arm/cpu/armv7/u-boot.lds b/arch/arm/cpu/armv7/u-boot.lds
index dbae54d4f8a340076d894608688e8b77bdab8af9..40ecf78b346a9d8fb87b20674fa5a93e41f30cbb 100644 (file)
--- a/arch/arm/cpu/armv7/u-boot.lds
+++ b/arch/arm/cpu/armv7/u-boot.lds
@@ -55,6 +55,8 @@ SECTIONS
 
        . = ALIGN(4);
 
+       __image_copy_end = .;
+
        .rel.dyn : {
                __rel_dyn_start = .;
                *(.rel*)