Patch by Anders Larsen, 09 Jan 2004:

[u-boot] / cpu / arm920t / start.S

diff --git a/cpu/arm920t/start.S b/cpu/arm920t/start.S
index ed16176a41ab1b2f9dec4dbcb4e58099c74abeb3..49264da99277325485fb24832e7485b190dbc712 100644 (file)
--- a/cpu/arm920t/start.S
+++ b/cpu/arm920t/start.S
@@ -25,7 +25,6 @@
  */
 
 
-
 #include <config.h>
 #include <version.h>
 
@@ -73,9 +72,6 @@ _fiq:                 .word fiq
  *************************************************************************
  */
 
-/*
- * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
- */
 _TEXT_BASE:
        .word   TEXT_BASE
 
@@ -84,24 +80,15 @@ _armboot_start:
        .word _start
 
 /*
- * Note: _armboot_end_data and _armboot_end are defined
- * by the (board-dependent) linker script.
- * _armboot_end_data is the first usable FLASH address after armboot
+ * These are defined in the board-specific linker script.
  */
-.globl _armboot_end_data
-_armboot_end_data:
-       .word armboot_end_data
-.globl _armboot_end
-_armboot_end:
-       .word armboot_end
+.globl _bss_start
+_bss_start:
+       .word __bss_start
 
-/*
- * _armboot_real_end is the first usable RAM address behind armboot
- * and the various stacks
- */
-.globl _armboot_real_end
-_armboot_real_end:
-       .word 0x0badc0de
+.globl _bss_end
+_bss_end:
+       .word _end
 
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
@@ -175,28 +162,44 @@ reset:
        bl      cpu_init_crit
 #endif
 
-relocate:
-       /*
-        * relocate armboot to RAM
-        */
-       adr     r0, _start              /* r0 <- current position of code */
+relocate:                              /* relocate U-Boot to RAM           */
+       adr     r0, _start              /* r0 <- current position of code   */
+       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, _armboot_end
-       sub     r2, r3, r2              /* r2 <- size of armboot */
-       ldr     r1, _TEXT_BASE          /* r1 <- destination address */
-       add     r2, r0, r2              /* r2 <- source end address */
+       ldr     r3, _bss_start
+       sub     r2, r3, r2              /* r2 <- size of armboot            */
+       add     r2, r0, r2              /* r2 <- source end address         */
 
-       /*
-        * r0 = source address
-        * r1 = target address
-        * r2 = source end address
-        */
 copy_loop:
-       ldmia   r0!, {r3-r10}
-       stmia   r1!, {r3-r10}
-       cmp     r0, r2
+       ldmia   r0!, {r3-r10}           /* copy from source address [r0]    */
+       stmia   r1!, {r3-r10}           /* copy to   target address [r1]    */
+       cmp     r0, r2                  /* until source end addreee [r2]    */
        ble     copy_loop
 
+       /* Set up the stack                                                 */
+stack_setup:
+       ldr     r0, _TEXT_BASE          /* upper 128 KiB: relocated uboot   */
+       sub     r0, r0, #CFG_MALLOC_LEN /* malloc area                      */
+       sub     r0, r0, #CFG_GBL_DATA_SIZE /* bdinfo                        */
+#ifdef CONFIG_USE_IRQ
+       sub     r0, r0, #(CONFIG_STACKSIZE_IRQ+CONFIG_STACKSIZE_FIQ)
+#endif
+       sub     sp, r0, #12             /* leave 3 words for abort-stack    */
+
+clear_bss:
+       ldr     r0, _bss_start          /* find start of bss segment        */
+       add     r0, r0, #4              /* start at first byte of bss       */
+       ldr     r1, _bss_end            /* stop here                        */
+       mov     r2, #0x00000000         /* clear                            */
+
+clbss_l:str    r2, [r0]                /* clear loop...                    */
+       add     r0, r0, #4
+       cmp     r0, r1
+       bne     clbss_l
+
 #if 0
        /* try doing this stuff after the relocation */
        ldr     r0, =pWTCON
@@ -218,11 +221,6 @@ copy_loop:
        /* END stuff after relocation */
 #endif
 
-       /* set up the stack */
-       ldr     r0, _armboot_end
-       add     r0, r0, #CONFIG_STACKSIZE
-       sub     sp, r0, #12             /* leave 3 words for abort-stack */
-
        ldr     pc, _start_armboot
 
 _start_armboot:        .word start_armboot
@@ -271,8 +269,6 @@ cpu_init_crit:
        mov     pc, lr
 
 
-
-
 /*
  *************************************************************************
  *
@@ -317,9 +313,9 @@ cpu_init_crit:
        .macro  bad_save_user_regs
        sub     sp, sp, #S_FRAME_SIZE
        stmia   sp, {r0 - r12}                  @ Calling r0-r12
-       ldr     r2, _armboot_end
-       add     r2, r2, #CONFIG_STACKSIZE
-       sub     r2, r2, #8
+       ldr     r2, _armboot_start
+       sub     r2, r2, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
+       sub     r2, r2, #(CFG_GBL_DATA_SIZE+8)  @ set base 2 words into abort stack
        ldmia   r2, {r2 - r3}                   @ get pc, cpsr
        add     r0, sp, #S_FRAME_SIZE           @ restore sp_SVC
 
@@ -350,9 +346,9 @@ cpu_init_crit:
        .endm
 
        .macro get_bad_stack
-       ldr     r13, _armboot_end               @ setup our mode stack
-       add     r13, r13, #CONFIG_STACKSIZE     @ resides at top of normal stack
-       sub     r13, r13, #8
+       ldr     r13, _armboot_start             @ setup our mode stack
+       sub     r13, r13, #(CONFIG_STACKSIZE+CFG_MALLOC_LEN)
+       sub     r13, r13, #(CFG_GBL_DATA_SIZE+8) @ reserved a couple spots in abort stack
 
        str     lr, [r13]                       @ save caller lr / spsr
        mrs     lr, spsr