Hello,
I have implemented kexec support for the mips architecture, the code is
available in the attached patch (for 2.6.18 kernel). This code works fine on
the mips boards I use at work (one in big endian and one in little endian) and
on qemu.
However it has not been tested on 64 bit mips and it may not work on
those architectures.
It may also not work on machines with more than 512 megabytes as the kexec
generic code may fill the page list with adresses over the 512 megabytes
limit (the mips boards I use only have 16mbytes and 32mbytes ram).
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
Do not hesitate to comment on this patch,
Regards,
--
Nicolas Schichan
diff -Nru linux-orig/arch/mips/Kconfig linux-work/arch/mips/Kconfig
--- linux-orig/arch/mips/Kconfig 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/Kconfig 2006-10-17 16:12:04.000000000 +0200
@@ -820,6 +820,23 @@
endchoice
+config KEXEC
+ bool "Kexec system call (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ kexec is a system call that implements the ability to shutdown your
+ current kernel, and to start another kernel. It is like a reboot
+ but it is indepedent of the system firmware. And like a reboot
+ you can start any kernel with it, not just Linux.
+
+ The name comes from the similiarity to the exec system call.
+
+ It is an ongoing process to be certain the hardware in a machine
+ is properly shutdown, so do not be surprised if this code does not
+ initially work for you. It may help to enable device hotplugging
+ support. As of this writing the exact hardware interface is
+ strongly in flux, so no good recommendation can be made.
+
source "arch/mips/ddb5xxx/Kconfig"
source "arch/mips/gt64120/ev64120/Kconfig"
source "arch/mips/jazz/Kconfig"
diff -Nru linux-orig/arch/mips/kernel/machine_kexec.c linux-work/arch/mips/kernel/machine_kexec.c
--- linux-orig/arch/mips/kernel/machine_kexec.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/machine_kexec.c 2006-10-18 14:03:59.000000000 +0200
@@ -0,0 +1,84 @@
+/*
+ * machine_kexec.c for kexec
+ * Created by <nschichan@xxxxxxxxxxxx> on Thu Oct 12 15:15:06 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/kexec.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+
+const extern unsigned char relocate_new_kernel[];
+const extern unsigned int relocate_new_kernel_size;
+
+extern unsigned long kexec_start_address;
+extern unsigned long kexec_indirection_page;
+
+int
+machine_kexec_prepare(struct kimage *kimage)
+{
+ return 0;
+}
+
+void
+machine_kexec_cleanup(struct kimage *kimage)
+{
+}
+
+void
+machine_shutdown(void)
+{
+}
+
+void
+machine_crash_shutdown(struct pt_regs *regs)
+{
+}
+
+void
+machine_kexec(struct kimage *image)
+{
+ unsigned long reboot_code_buffer;
+ unsigned long entry;
+ unsigned long *ptr;
+
+ reboot_code_buffer =
+ (unsigned long)page_address(image->control_code_page);
+
+ kexec_start_address = image->start;
+ kexec_indirection_page = phys_to_virt(image->head & PAGE_MASK);
+
+ memcpy((void*)reboot_code_buffer, relocate_new_kernel,
+ relocate_new_kernel_size);
+
+ /*
+ * The generic kexec code builds a page list with physical
+ * addresses. they are directly accessible through KSEG0,
+ * hence the pys_to_virt() call.
+ */
+ for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
+ ptr = (entry & IND_INDIRECTION) ?
+ phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
+ if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
+ *ptr & IND_DESTINATION)
+ *ptr = phys_to_virt(*ptr);
+ }
+
+ /*
+ * we do not want to be bothered.
+ */
+ local_irq_disable();
+
+ flush_icache_range(reboot_code_buffer,
+ reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
+
+ printk("Will call new kernel at %08x\n", image->start);
+ printk("Bye ...\n");
+ flush_cache_all();
+ ((void (*)(void))reboot_code_buffer)();
+}
diff -Nru linux-orig/arch/mips/kernel/Makefile linux-work/arch/mips/kernel/Makefile
--- linux-orig/arch/mips/kernel/Makefile 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/Makefile 2006-10-17 15:55:11.000000000 +0200
@@ -66,6 +66,8 @@
obj-$(CONFIG_I8253) += i8253.o
+obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
+
CFLAGS_cpu-bugs64.o = $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
EXTRA_AFLAGS := $(CFLAGS)
diff -Nru linux-orig/arch/mips/kernel/relocate_kernel.S linux-work/arch/mips/kernel/relocate_kernel.S
--- linux-orig/arch/mips/kernel/relocate_kernel.S 1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/relocate_kernel.S 2006-10-17 20:01:06.000000000 +0200
@@ -0,0 +1,80 @@
+/*
+ * relocate_kernel.S for kexec
+ * Created by <nschichan@xxxxxxxxxxxx> 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
diff -Nru linux-orig/arch/mips/kernel/scall32-o32.S linux-work/arch/mips/kernel/scall32-o32.S
--- linux-orig/arch/mips/kernel/scall32-o32.S 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall32-o32.S 2006-10-17 16:23:21.000000000 +0200
@@ -662,6 +662,7 @@
sys sys_tee 4
sys sys_vmsplice 4
sys sys_move_pages 6
+ sys sys_kexec_load 1
.endm
/* We pre-compute the number of _instruction_ bytes needed to
diff -Nru linux-orig/arch/mips/kernel/scall64-64.S linux-work/arch/mips/kernel/scall64-64.S
--- linux-orig/arch/mips/kernel/scall64-64.S 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-64.S 2006-10-17 15:57:15.000000000 +0200
@@ -466,3 +466,4 @@
PTR sys_tee /* 5265 */
PTR sys_vmsplice
PTR sys_move_pages
+ PTR sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-n32.S linux-work/arch/mips/kernel/scall64-n32.S
--- linux-orig/arch/mips/kernel/scall64-n32.S 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-n32.S 2006-10-17 15:58:59.000000000 +0200
@@ -392,3 +392,4 @@
PTR sys_tee
PTR sys_vmsplice /* 6271 */
PTR sys_move_pages
+ PTR sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-o32.S linux-work/arch/mips/kernel/scall64-o32.S
--- linux-orig/arch/mips/kernel/scall64-o32.S 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-o32.S 2006-10-17 15:59:23.000000000 +0200
@@ -514,4 +514,5 @@
PTR sys_tee
PTR sys_vmsplice
PTR compat_sys_move_pages
+ PTR sys_kexec_load
.size sys_call_table,.-sys_call_table
diff -Nru linux-orig/include/asm-mips/kexec.h linux-work/include/asm-mips/kexec.h
--- linux-orig/include/asm-mips/kexec.h 1970-01-01 01:00:00.000000000 +0100
+++ linux-work/include/asm-mips/kexec.h 2006-10-18 12:29:12.000000000 +0200
@@ -0,0 +1,32 @@
+/*
+ * kexec.h for kexec
+ * Created by <nschichan@xxxxxxxxxxxx> on Thu Oct 12 14:59:34 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#ifndef _MIPS_KEXEC
+# define _MIPS_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (0x20000000)
+ /* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (0x20000000)
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+/* The native architecture */
+#define KEXEC_ARCH KEXEC_ARCH_MIPS
+
+#define MAX_NOTE_BYTES 1024
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+ struct pt_regs *oldregs)
+{
+ /* Dummy implementation for now */
+}
+
+#endif /* !_MIPS_KEXEC */
diff -Nru linux-orig/include/asm-mips/unistd.h linux-work/include/asm-mips/unistd.h
--- linux-orig/include/asm-mips/unistd.h 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/asm-mips/unistd.h 2006-10-17 16:07:57.000000000 +0200
@@ -329,16 +329,17 @@
#define __NR_tee (__NR_Linux + 306)
#define __NR_vmsplice (__NR_Linux + 307)
#define __NR_move_pages (__NR_Linux + 308)
+#define __NR_kexec_load (__NR_Linux + 309)
/*
* Offset of the last Linux o32 flavoured syscall
*/
-#define __NR_Linux_syscalls 308
+#define __NR_Linux_syscalls 309
#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
#define __NR_O32_Linux 4000
-#define __NR_O32_Linux_syscalls 308
+#define __NR_O32_Linux_syscalls 309
#if _MIPS_SIM == _MIPS_SIM_ABI64
@@ -614,16 +615,17 @@
#define __NR_tee (__NR_Linux + 265)
#define __NR_vmsplice (__NR_Linux + 266)
#define __NR_move_pages (__NR_Linux + 267)
+#define __NR_kexec_load (__NR_Linux + 268)
/*
* Offset of the last Linux 64-bit flavoured syscall
*/
-#define __NR_Linux_syscalls 267
+#define __NR_Linux_syscalls 268
#endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
#define __NR_64_Linux 5000
-#define __NR_64_Linux_syscalls 267
+#define __NR_64_Linux_syscalls 268
#if _MIPS_SIM == _MIPS_SIM_NABI32
@@ -903,16 +905,16 @@
#define __NR_tee (__NR_Linux + 269)
#define __NR_vmsplice (__NR_Linux + 270)
#define __NR_move_pages (__NR_Linux + 271)
-
+#define __NR_kexec_load (__Nr_Linux + 272)
/*
* Offset of the last N32 flavoured syscall
*/
-#define __NR_Linux_syscalls 271
+#define __NR_Linux_syscalls 272
#endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
#define __NR_N32_Linux 6000
-#define __NR_N32_Linux_syscalls 271
+#define __NR_N32_Linux_syscalls 272
#ifdef __KERNEL__
diff -Nru linux-orig/include/linux/kexec.h linux-work/include/linux/kexec.h
--- linux-orig/include/linux/kexec.h 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/linux/kexec.h 2006-10-17 16:21:49.000000000 +0200
@@ -122,6 +122,8 @@
#define KEXEC_ARCH_IA_64 (50 << 16)
#define KEXEC_ARCH_S390 (22 << 16)
#define KEXEC_ARCH_SH (42 << 16)
+#define KEXEC_ARCH_MIPS_LE (10 << 16)
+#define KEXEC_ARCH_MIPS ( 8 << 16)
#define KEXEC_FLAGS (KEXEC_ON_CRASH) /* List of defined/legal kexec flags */
diff -Nru linux-orig/Makefile linux-work/Makefile
--- linux-orig/Makefile 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/Makefile 2006-10-17 16:09:02.000000000 +0200
@@ -149,10 +149,11 @@
# then ARCH is assigned, getting whatever value it gets normally, and
# SUBARCH is subsequently ignored.
-SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
- -e s/arm.*/arm/ -e s/sa110/arm/ \
- -e s/s390x/s390/ -e s/parisc64/parisc/ \
- -e s/ppc.*/powerpc/ -e s/mips.*/mips/ )
+SUBARCH := mips
+# $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
+# -e s/arm.*/arm/ -e s/sa110/arm/ \
+# -e s/s390x/s390/ -e s/parisc64/parisc/ \
+# -e s/ppc.*/powerpc/ -e s/mips.*/mips/ )
# Cross compiling and selecting different set of gcc/bin-utils
# ---------------------------------------------------------------------------
