powerpc: Make the 64-bit kernel as a position-independent executable

[linux-2.6-omap-h63xx.git] / arch / powerpc / kernel / head_64.S

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 6cdfd44d8efe6eeb5371c75fee7392b3515aa04f..84856bee33a54a5bc58d7c99edf67286ddd281e0 100644 (file)
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -1360,6 +1360,12 @@ _INIT_STATIC(__boot_from_prom)
         */
        rldicr  r1,r1,0,59
 
+#ifdef CONFIG_RELOCATABLE
+       /* Relocate code for where we are now */
+       mr      r3,r26
+       bl      .relocate
+#endif
+
        /* Restore parameters */
        mr      r3,r31
        mr      r4,r30
@@ -1368,11 +1374,19 @@ _INIT_STATIC(__boot_from_prom)
        mr      r7,r27
 
        /* Do all of the interaction with OF client interface */
+       mr      r8,r26
        bl      .prom_init
        /* We never return */
        trap
 
 _STATIC(__after_prom_start)
+#ifdef CONFIG_RELOCATABLE
+       /* process relocations for the final address of the kernel */
+       lis     r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
+       sldi    r25,r25,32
+       mr      r3,r25
+       bl      .relocate
+#endif
 
 /*
  * We need to run with _stext at physical address PHYSICAL_START.
@@ -1381,10 +1395,9 @@ _STATIC(__after_prom_start)
  *
  * Note: This process overwrites the OF exception vectors.
  */
-       LOAD_REG_IMMEDIATE(r3, PHYSICAL_START)  /* target addr */
-       cmpd    r3,r26                  /* In some cases the loader may  */
+       li      r3,0                    /* target addr */
+       mr.     r4,r26                  /* In some cases the loader may  */
        beq     9f                      /* have already put us at zero */
-       mr      r4,r26                  /* source address */
        lis     r5,(copy_to_here - _stext)@ha
        addi    r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
        li      r6,0x100                /* Start offset, the first 0x100 */
@@ -1617,6 +1630,13 @@ _INIT_STATIC(start_here_multiplatform)
        ori     r6,r6,MSR_RI
        mtmsrd  r6                      /* RI on */
 
+#ifdef CONFIG_RELOCATABLE
+       /* Save the physical address we're running at in kernstart_addr */
+       LOAD_REG_ADDR(r4, kernstart_addr)
+       clrldi  r0,r25,2
+       std     r0,0(r4)
+#endif
+
        /* The following gets the stack set up with the regs */
        /* pointing to the real addr of the kernel stack.  This is   */
        /* all done to support the C function call below which sets  */