MIPS: fix setup of initial stack frame

To get correct stack walking and backtrace functionality in gdb,
registers fp and ra should be initialized before calling board_init_f
or board_init_r. Thus allocating stack space and zeroing it as it is
currently done in board.c becomes obsolete.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

diff --git a/arch/mips/cpu/mips32/start.S b/arch/mips/cpu/mips32/start.S
index 68e59b596f1146f605a91383c7dd950945fddc2f..384ea26022bcf5b907a8eaf541466bbb56a3612a 100644 (file)
--- a/arch/mips/cpu/mips32/start.S
+++ b/arch/mips/cpu/mips32/start.S
@@ -136,10 +136,11 @@ reset:
 
        /* Set up temporary stack */
        li      sp, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET
+       move    fp, sp
 
        la      t9, board_init_f
        jr      t9
-        nop
+        move   ra, zero
 
 /*
  * void relocate_code (addr_sp, gd, addr_moni)
@@ -155,6 +156,7 @@ reset:
        .ent    relocate_code
 relocate_code:
        move    sp, a0                  # set new stack pointer
+       move    fp, sp
 
        move    s0, a1                  # save gd in s0
        move    s2, a2                  # save destination address in s2
@@ -260,8 +262,9 @@ in_ram:
         addi   t1, 4
 
        move    a0, s0                  # a0 <-- gd
+       move    a1, s2
        la      t9, board_init_r
        jr      t9
-        move   a1, s2
+        move   ra, zero
 
        .end    relocate_code

diff --git a/arch/mips/cpu/mips64/start.S b/arch/mips/cpu/mips64/start.S
index 92954e1c907bf9dddb64aa433aa6374cd324205a..6ff714e8ed4fa2f177ecdc02d9fa8989dd1fe783 100644 (file)
--- a/arch/mips/cpu/mips64/start.S
+++ b/arch/mips/cpu/mips64/start.S
@@ -130,10 +130,11 @@ reset:
 
        /* Set up temporary stack */
        dli     sp, CONFIG_SYS_SDRAM_BASE + CONFIG_SYS_INIT_SP_OFFSET
+       move    fp, sp
 
        dla     t9, board_init_f
        jr      t9
-        nop
+        move   ra, zero
 
 /*
  * void relocate_code (addr_sp, gd, addr_moni)
@@ -149,6 +150,7 @@ reset:
        .ent    relocate_code
 relocate_code:
        move    sp, a0                  # set new stack pointer
+       move    fp, sp
 
        move    s0, a1                  # save gd in s0
        move    s2, a2                  # save destination address in s2
@@ -254,8 +256,9 @@ in_ram:
         daddi  t1, 8
 
        move    a0, s0                  # a0 <-- gd
+       move    a1, s2
        dla     t9, board_init_r
        jr      t9
-        move   a1, s2
+        move   ra, zero
 
        .end    relocate_code