arm: optimize relocate_code routine

Use section symbols directly
Drop support for R_ARM_ABS32 record types
Eliminate unneeded intermediate registers
Optimize relocation table iteration

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
Tested-by: Lubomir Popov <lpopov@mm-sol.com>
Tested-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>

diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S
index 3f444c1d267aaa9c66505cc704f8fe57bf99bc25..949b9e8025b994cb8e6a9d85e63a920387e11ba7 100644 (file)
--- a/arch/arm/lib/relocate.S
+++ b/arch/arm/lib/relocate.S
@@ -37,19 +37,15 @@
  */
 
 ENTRY(relocate_code)
-       mov     r6, r0  /* save addr of destination */
-
-       ldr     r0, =__image_copy_start /* r0 <- SRC &__image_copy_start */
-       subs    r9, r6, r0              /* r9 <- relocation offset */
+       ldr     r1, =__image_copy_start /* r1 <- SRC &__image_copy_start */
+       subs    r9, r0, r1              /* r9 <- relocation offset */
        beq     relocate_done           /* skip relocation */
-       mov     r1, r6                  /* r1 <- scratch for copy loop */
-       adr     r7, relocate_code       /* r7 <- SRC &relocate_code */
        ldr     r2, =__image_copy_end   /* r2 <- SRC &__image_copy_end */
 
 copy_loop:
-       ldmia   r0!, {r10-r11}          /* copy from source address [r0]    */
-       stmia   r1!, {r10-r11}          /* copy to   target address [r1]    */
-       cmp     r0, r2                  /* until source end address [r2]    */
+       ldmia   r1!, {r10-r11}          /* copy from source address [r1]    */
+       stmia   r0!, {r10-r11}          /* copy to   target address [r0]    */
+       cmp     r1, r2                  /* until source end address [r2]    */
        blo     copy_loop
 
        /*
@@ -58,21 +54,17 @@ copy_loop:
        ldr     r2, =__rel_dyn_start    /* r2 <- SRC &__rel_dyn_start */
        ldr     r3, =__rel_dyn_end      /* r3 <- SRC &__rel_dyn_end */
 fixloop:
-       ldr     r0, [r2]                /* r0 <- SRC location to fix up */
-       add     r0, r0, r9              /* r0 <- DST location to fix up */
-       ldr     r1, [r2, #4]
-       and     r7, r1, #0xff
-       cmp     r7, #23                 /* relative fixup? */
-       beq     fixrel
-       /* ignore unknown type of fixup */
-       b       fixnext
-fixrel:
+       ldmia   r2!, {r0-r1}            /* (r0,r1) <- (SRC location,fixup) */
+       and     r1, r1, #0xff
+       cmp     r1, #23                 /* relative fixup? */
+       bne     fixnext
+
        /* relative fix: increase location by offset */
+       add     r0, r0, r9
        ldr     r1, [r0]
        add     r1, r1, r9
-fixnext:
        str     r1, [r0]
-       add     r2, r2, #8              /* each rel.dyn entry is 8 bytes */
+fixnext:
        cmp     r2, r3
        blo     fixloop