[MIPS] Add support for kexec
A tiny userland application loading the kernel and invoking kexec_load for
mips is available here:
http://chac.le-poulpe.net/~nico/kexec/kexec-2006-10-18.tar.gz
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/relocate_kernel.S b/arch/mips/kernel/relocate_kernel.S
new file mode 100644
index 0000000..a3f0d00
--- /dev/null
+++ b/arch/mips/kernel/relocate_kernel.S
@@ -0,0 +1,80 @@
+/*
+ * relocate_kernel.S for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/regdef.h>
+#include <asm/page.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/addrspace.h>
+
+ .globl relocate_new_kernel
+relocate_new_kernel:
+
+ PTR_L s0, kexec_indirection_page
+ PTR_L s1, kexec_start_address
+
+process_entry:
+ PTR_L s2, (s0)
+ PTR_ADD s0, s0, SZREG
+
+ /* destination page */
+ and s3, s2, 0x1
+ beq s3, zero, 1f
+ and s4, s2, ~0x1 /* store destination addr in s4 */
+ move a0, s4
+ b process_entry
+
+1:
+ /* indirection page, update s0 */
+ and s3, s2, 0x2
+ beq s3, zero, 1f
+ and s0, s2, ~0x2
+ b process_entry
+
+1:
+ /* done page */
+ and s3, s2, 0x4
+ beq s3, zero, 1f
+ b done
+1:
+ /* source page */
+ and s3, s2, 0x8
+ beq s3, zero, process_entry
+ and s2, s2, ~0x8
+ li s6, (1 << PAGE_SHIFT) / SZREG
+
+copy_word:
+ /* copy page word by word */
+ REG_L s5, (s2)
+ REG_S s5, (s4)
+ INT_ADD s4, s4, SZREG
+ INT_ADD s2, s2, SZREG
+ INT_SUB s6, s6, 1
+ beq s6, zero, process_entry
+ b copy_word
+ b process_entry
+
+done:
+ /* jump to kexec_start_address */
+ j s1
+
+ .globl kexec_start_address
+kexec_start_address:
+ .long 0x0
+
+ .globl kexec_indirection_page
+kexec_indirection_page:
+ .long 0x0
+
+relocate_new_kernel_end:
+
+ .globl relocate_new_kernel_size
+relocate_new_kernel_size:
+ .long relocate_new_kernel_end - relocate_new_kernel