Update from 2013.01 to 2013.07

[karo-tx-uboot.git] / arch / arm / lib / relocate.S

diff --git a/arch/arm/lib/relocate.S b/arch/arm/lib/relocate.S
new file mode 100644 (file)
index 0000000..90d612f
--- /dev/null
+++ b/arch/arm/lib/relocate.S
@@ -0,0 +1,74 @@
+/*
+ *  relocate - common relocation function for ARM U-Boot
+ *
+ *  Copyright (c) 2013  Albert ARIBAUD <albert.u.boot@aribaud.net>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <linux/linkage.h>
+
+/*
+ * void relocate_code(addr_moni)
+ *
+ * This function relocates the monitor code.
+ *
+ * NOTE:
+ * To prevent the code below from containing references with an R_ARM_ABS32
+ * relocation record type, we never refer to linker-defined symbols directly.
+ * Instead, we declare literals which contain their relative location with
+ * respect to relocate_code, and at run time, add relocate_code back to them.
+ */
+
+ENTRY(relocate_code)
+       ldr     r1, =_start     /* r1 <- SRC &__image_copy_start */
+       subs    r9, r0, r1              /* r9 <- relocation offset */
+       beq     relocate_done           /* skip relocation */
+       ldr     r2, =__image_copy_end   /* r2 <- SRC &__image_copy_end */
+
+copy_loop:
+       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
+
+       /*
+        * fix .rel.dyn relocations
+        */
+       ldr     r2, =__rel_dyn_start    /* r2 <- SRC &__rel_dyn_start */
+       ldr     r3, =__rel_dyn_end      /* r3 <- SRC &__rel_dyn_end */
+fixloop:
+       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
+       str     r1, [r0]
+fixnext:
+       cmp     r2, r3
+       blo     fixloop
+
+relocate_done:
+
+#ifdef __XSCALE__
+       /*
+        * On xscale, icache must be invalidated and write buffers drained,
+        * even with cache disabled - 4.2.7 of xscale core developer's manual
+        */
+       mcr     p15, 0, r0, c7, c7, 0   /* invalidate icache */
+       mcr     p15, 0, r0, c7, c10, 4  /* drain write buffer */
+#endif
+
+       /* ARMv4- don't know bx lr but the assembler fails to see that */
+
+#ifdef __ARM_ARCH_4__
+        mov        pc, lr
+#else
+        bx        lr
+#endif
+
+ENDPROC(relocate_code)