powerpc: enable the relocatable support for the fsl booke 32bit kernel
This is based on the codes in the head_44x.S. The difference is that
the init tlb size we used is 64M. With this patch we can only load the
kernel at address between memstart_addr ~ memstart_addr + 64M. We will
fix this restriction in the following patches.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 07ba45b..ce4a116 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -241,4 +241,32 @@
/* 64M mapped initially according to head_fsl_booke.S */
memblock_set_current_limit(min_t(u64, limit, 0x04000000));
}
+
+#ifdef CONFIG_RELOCATABLE
+notrace void __init relocate_init(phys_addr_t start)
+{
+ unsigned long base = KERNELBASE;
+
+ /*
+ * Relocatable kernel support based on processing of dynamic
+ * relocation entries.
+ * Compute the virt_phys_offset :
+ * virt_phys_offset = stext.run - kernstart_addr
+ *
+ * stext.run = (KERNELBASE & ~0x3ffffff) + (kernstart_addr & 0x3ffffff)
+ * When we relocate, we have :
+ *
+ * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
+ *
+ * hence:
+ * virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
+ * (kernstart_addr & ~0x3ffffff)
+ *
+ */
+ kernstart_addr = start;
+ start &= ~0x3ffffff;
+ base &= ~0x3ffffff;
+ virt_phys_offset = base - start;
+}
+#endif
#endif