arm926ejs: add nand_spl boot support

Add CONFIG_PRELOADER/CONFIG_NAND_SPL support for nand booting
to arm926ejs/start.S

This is derived from CONFIG_PRELOADER support in arm1136/start.S

Signed-off-by: John Rigby <jcrigby@gmail.com>

diff --git a/cpu/arm926ejs/start.S b/cpu/arm926ejs/start.S
index 4421b6a99015dba90f58f39540379af2cad322bf..3b81151f49cecaa0b42875ed031b8e3f313cc1c6 100644 (file)
--- a/cpu/arm926ejs/start.S
+++ b/cpu/arm926ejs/start.S
@@ -53,6 +53,27 @@
 .globl _start
 _start:
        b       reset
+#ifdef CONFIG_PRELOADER
+/* No exception handlers in preloader */
+       ldr     pc, _hang
+       ldr     pc, _hang
+       ldr     pc, _hang
+       ldr     pc, _hang
+       ldr     pc, _hang
+       ldr     pc, _hang
+       ldr     pc, _hang
+
+_hang:
+       .word   do_hang
+/* pad to 64 byte boundary */
+       .word   0x12345678
+       .word   0x12345678
+       .word   0x12345678
+       .word   0x12345678
+       .word   0x12345678
+       .word   0x12345678
+       .word   0x12345678
+#else
        ldr     pc, _undefined_instruction
        ldr     pc, _software_interrupt
        ldr     pc, _prefetch_abort
@@ -76,6 +97,7 @@ _irq:
 _fiq:
        .word fiq
 
+#endif /* CONFIG_PRELOADER */
        .balignl 16,0xdeadbeef
 
 
@@ -150,7 +172,6 @@ relocate:                           /* relocate U-Boot to RAM           */
        ldr     r1, _TEXT_BASE          /* test if we run from flash or RAM */
        cmp     r0, r1                  /* don't reloc during debug         */
        beq     stack_setup
-
        ldr     r2, _armboot_start
        ldr     r3, _bss_start
        sub     r2, r3, r2              /* r2 <- size of armboot            */
@@ -166,11 +187,14 @@ copy_loop:
        /* Set up the stack                                                 */
 stack_setup:
        ldr     r0, _TEXT_BASE          /* upper 128 KiB: relocated uboot   */
+       sub     sp, r0, #128            /* leave 32 words for abort-stack   */
+#ifndef CONFIG_PRELOADER
        sub     r0, r0, #CONFIG_SYS_MALLOC_LEN  /* malloc area                      */
        sub     r0, r0, #CONFIG_SYS_GBL_DATA_SIZE /* bdinfo                        */
 #ifdef CONFIG_USE_IRQ
        sub     r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
 #endif
+#endif /* CONFIG_PRELOADER */
        sub     sp, r0, #12             /* leave 3 words for abort-stack    */
        bic     sp, r0, #7              /* 8-byte align stack for ABI compliance */
 
@@ -179,6 +203,7 @@ clear_bss:
        ldr     r1, _bss_end            /* stop here                        */
        mov     r2, #0x00000000         /* clear                            */
 
+#ifndef CONFIG_PRELOADER
 clbss_l:str    r2, [r0]                /* clear loop...                    */
        add     r0, r0, #4
        cmp     r0, r1
@@ -186,11 +211,16 @@ clbss_l:str       r2, [r0]                /* clear loop...                    */
 
        bl coloured_LED_init
        bl red_LED_on
+#endif /* CONFIG_PRELOADER */
 
        ldr     pc, _start_armboot
 
 _start_armboot:
+#ifdef CONFIG_NAND_SPL
+       .word nand_boot
+#else
        .word start_armboot
+#endif /* CONFIG_NAND_SPL */
 
 
 /*
@@ -231,6 +261,7 @@ cpu_init_crit:
        mov     pc, lr          /* back to my caller */
 #endif /* CONFIG_SKIP_LOWLEVEL_INIT */
 
+#ifndef CONFIG_PRELOADER
 /*
  *************************************************************************
  *
@@ -332,10 +363,18 @@ cpu_init_crit:
        .macro get_fiq_stack                    @ setup FIQ stack
        ldr     sp, FIQ_STACK_START
        .endm
+#endif /* CONFIG_PRELOADER */
 
 /*
  * exception handlers
  */
+#ifdef CONFIG_PRELOADER
+       .align  5
+do_hang:
+       ldr     sp, _TEXT_BASE                  /* switch to abort stack */
+1:
+       bl      1b                              /* hang and never return */
+#else  /* !CONFIG_PRELOADER */
        .align  5
 undefined_instruction:
        get_bad_stack
@@ -398,3 +437,4 @@ fiq:
        bl      do_fiq
 
 #endif
+#endif /* CONFIG_PRELOADER */