AVR32: Relocate u-boot to SDRAM
Relocate the u-boot image into SDRAM like everyone else does. This
means that we can handle much larger .data and .bss than we used to.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/cpu/at32ap/start.S b/cpu/at32ap/start.S
index 4ae0b54..ab8c2b7 100644
--- a/cpu/at32ap/start.S
+++ b/cpu/at32ap/start.S
@@ -70,32 +70,12 @@
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 @@
.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_