AVR32: Relocate u-boot to SDRAM

[platform/kernel/u-boot.git] / cpu / at32ap / start.S

diff --git a/cpu/at32ap/start.S b/cpu/at32ap/start.S
index 4ae0b54..ab8c2b7 100644 (file)
--- a/cpu/at32ap/start.S
+++ b/cpu/at32ap/start.S
@@ -70,32 +70,12 @@ _start:
 
 2:     lddpc   sp, sp_init
 
-       /*
-        * Relocate the data section and initialize .bss.  Everything
-        * is guaranteed to be at least doubleword aligned by the
-        * linker script.
-        */
-       lddpc   r12, .Ldata_vma
-       lddpc   r11, .Ldata_lma
-       lddpc   r10, .Ldata_end
-       sub     r10, r12
-4:     ld.d    r8, r11++
-       sub     r10, 8
-       st.d    r12++, r8
-       brne    4b
-
-       mov     r8, 0
-       mov     r9, 0
-       lddpc   r10, .Lbss_end
-       sub     r10, r12
-4:     sub     r10, 8
-       st.d    r12++, r8
-       brne    4b
-
        /* Initialize the GOT pointer */
        lddpc   r6, got_init
 3:     rsub    r6, pc
-       ld.w    pc, r6[board_init_f@got]
+
+       /* Let's go */
+       rjmp    board_init_f
 
        .align  2
        .type   sp_init,@object
@@ -103,11 +83,82 @@ sp_init:
        .long   CFG_INIT_SP_ADDR
 got_init:
        .long   3b - _GLOBAL_OFFSET_TABLE_
-.Ldata_lma:
-       .long   __data_lma
-.Ldata_vma:
-       .long   _data
-.Ldata_end:
-       .long   _edata
-.Lbss_end:
-       .long   _end
+
+       /*
+        * void relocate_code(new_sp, new_gd, monitor_addr)
+        *
+        * Relocate the u-boot image into RAM and continue from there.
+        * Does not return.
+        */
+       .global relocate_code
+       .type   relocate_code,@function
+relocate_code:
+       mov     sp, r12         /* use new stack */
+       mov     r12, r11        /* save new_gd */
+       mov     r11, r10        /* save destination address */
+
+       /* copy .text section and flush the cache along the way */
+       lda.w   r8, _text
+       lda.w   r9, _etext
+       sub     lr, r10, r8     /* relocation offset */
+
+1:     ldm     r8++, r0-r3
+       stm     r10, r0-r3
+       sub     r10, -16
+       ldm     r8++, r0-r3
+       stm     r10, r0-r3
+       sub     r10, -16
+       cp.w    r8, r9
+       cache   r10[-4], 0x0d   /* dcache clean/invalidate */
+       cache   r10[-4], 0x01   /* icache invalidate */
+       brlt    1b
+
+       /* flush write buffer */
+       sync    0
+
+       /* copy data sections */
+       lda.w   r9, _edata
+1:     ld.d    r0, r8++
+       st.d    r10++, r0
+       cp.w    r8, r9
+       brlt    1b
+
+       /* zero out .bss */
+       mov     r0, 0
+       mov     r1, 0
+       lda.w   r9, _end
+       sub     r9, r8
+1:     st.d    r10++, r0
+       sub     r9, 8
+       brgt    1b
+
+       /* jump to RAM */
+       sub     r0, pc, . - in_ram
+       add     pc, r0, lr
+
+       .align  2
+in_ram:
+       /* find the new GOT and relocate it */
+       lddpc   r6, got_init_reloc
+3:     rsub    r6, pc
+       mov     r8, r6
+       lda.w   r9, _egot
+       lda.w   r10, _got
+       sub     r9, r10
+1:     ld.w    r0, r8[0]
+       add     r0, lr
+       st.w    r8++, r0
+       sub     r9, 4
+       brgt    1b
+
+       /* Move the exception handlers */
+       mfsr    r2, SYSREG_EVBA
+       add     r2, lr
+       mtsr    SYSREG_EVBA, r2
+
+       /* Do the rest of the initialization sequence */
+       call    board_init_r
+
+       .align  2
+got_init_reloc:
+       .long   3b - _GLOBAL_OFFSET_TABLE_