diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 14 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/calls.S | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/machine_kexec.c | 78 | ||||
| -rw-r--r-- | arch/arm/kernel/relocate_kernel.S | 74 |
5 files changed, 168 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 6783c2e5512..a8298949d16 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -738,6 +738,20 @@ config XIP_PHYS_ADDR be linked for and stored to. This address is dependent on your own flash usage. +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. + + 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. + endmenu if (ARCH_SA1100 || ARCH_INTEGRATOR || ARCH_OMAP || ARCH_IMX ) diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index ab06a86e85d..d5002889773 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o obj-$(CONFIG_ISA_DMA) += dma-isa.o obj-$(CONFIG_PCI) += bios32.o isa.o obj-$(CONFIG_SMP) += smp.o +obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index f7598cbc7ec..ae89cdd82b1 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -356,6 +356,7 @@ CALL(sys_move_pages) /* 345 */ CALL(sys_getcpu) CALL(sys_ni_syscall) /* eventually epoll_pwait */ + CALL(sys_kexec_load) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted diff --git a/arch/arm/kernel/machine_kexec.c b/arch/arm/kernel/machine_kexec.c new file mode 100644 index 00000000000..863c66454f2 --- /dev/null +++ b/arch/arm/kernel/machine_kexec.c @@ -0,0 +1,78 @@ +/* + * machine_kexec.c - handle transition of Linux booting another kernel + */ + +#include <linux/mm.h> +#include <linux/kexec.h> +#include <linux/delay.h> +#include <linux/reboot.h> +#include <asm/pgtable.h> +#include <asm/pgalloc.h> +#include <asm/mmu_context.h> +#include <asm/io.h> +#include <asm/cacheflush.h> +#include <asm/mach-types.h> + +const extern unsigned char relocate_new_kernel[]; +const extern unsigned int relocate_new_kernel_size; + +extern void setup_mm_for_reboot(char mode); + +extern unsigned long kexec_start_address; +extern unsigned long kexec_indirection_page; +extern unsigned long kexec_mach_type; + +/* + * Provide a dummy crash_notes definition while crash dump arrives to arm. + * This prevents breakage of crash_notes attribute in kernel/ksysfs.c. + */ + +int machine_kexec_prepare(struct kimage *image) +{ + return 0; +} + +void machine_kexec_cleanup(struct kimage *image) +{ +} + +void machine_shutdown(void) +{ +} + +void machine_crash_shutdown(struct pt_regs *regs) +{ +} + +void machine_kexec(struct kimage *image) +{ + unsigned long page_list; + unsigned long reboot_code_buffer_phys; + void *reboot_code_buffer; + + + page_list = image->head & PAGE_MASK; + + /* we need both effective and real address here */ + reboot_code_buffer_phys = + page_to_pfn(image->control_code_page) << PAGE_SHIFT; + reboot_code_buffer = page_address(image->control_code_page); + + /* Prepare parameters for reboot_code_buffer*/ + kexec_start_address = image->start; + kexec_indirection_page = page_list; + kexec_mach_type = machine_arch_type; + + /* copy our kernel relocation code to the control code page */ + memcpy(reboot_code_buffer, + relocate_new_kernel, relocate_new_kernel_size); + + + flush_icache_range((unsigned long) reboot_code_buffer, + (unsigned long) reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE); + printk(KERN_INFO "Bye!\n"); + + cpu_proc_fin(); + setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/ + cpu_reset(reboot_code_buffer_phys); +} diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S new file mode 100644 index 00000000000..7baadae7cb2 --- /dev/null +++ b/arch/arm/kernel/relocate_kernel.S @@ -0,0 +1,74 @@ +/* + * relocate_kernel.S - put the kernel image in place to boot + */ + +#include <asm/kexec.h> + + .globl relocate_new_kernel +relocate_new_kernel: + + ldr r0,kexec_indirection_page + ldr r1,kexec_start_address + + +0: /* top, read another word for the indirection page */ + ldr r3, [r0],#4 + + /* Is it a destination page. Put destination address to r4 */ + tst r3,#1,0 + beq 1f + bic r4,r3,#1 + b 0b +1: + /* Is it an indirection page */ + tst r3,#2,0 + beq 1f + bic r0,r3,#2 + b 0b +1: + + /* are we done ? */ + tst r3,#4,0 + beq 1f + b 2f + +1: + /* is it source ? */ + tst r3,#8,0 + beq 0b + bic r3,r3,#8 + mov r6,#1024 +9: + ldr r5,[r3],#4 + str r5,[r4],#4 + subs r6,r6,#1 + bne 9b + b 0b + +2: + /* Jump to relocated kernel */ + mov lr,r1 + mov r0,#0 + ldr r1,kexec_mach_type + mov r2,#0 + mov pc,lr + + .globl kexec_start_address +kexec_start_address: + .long 0x0 + + .globl kexec_indirection_page +kexec_indirection_page: + .long 0x0 + + .globl kexec_mach_type +kexec_mach_type: + .long 0x0 + +relocate_new_kernel_end: + + .globl relocate_new_kernel_size +relocate_new_kernel_size: + .long relocate_new_kernel_end - relocate_new_kernel + + |