299 lines
		
	
	
		
			7.9 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			299 lines
		
	
	
		
			7.9 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From d8582dcf1ed66eee88a11e4760f42c0d6c8822be Mon Sep 17 00:00:00 2001
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From: Yousong Zhou <yszhou4tech@gmail.com>
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Date: Sat, 31 Jan 2015 22:26:03 +0800
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Subject: [PATCH 331/331] MIPS: kexec: Accept command line parameters from
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 userspace.
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Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
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---
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 arch/mips/kernel/machine_kexec.c   |  153 +++++++++++++++++++++++++++++++-----
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 arch/mips/kernel/machine_kexec.h   |   20 +++++
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 arch/mips/kernel/relocate_kernel.S |   21 +++--
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 3 files changed, 167 insertions(+), 27 deletions(-)
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 create mode 100644 arch/mips/kernel/machine_kexec.h
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--- a/arch/mips/kernel/machine_kexec.c
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+++ b/arch/mips/kernel/machine_kexec.c
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@@ -10,45 +10,145 @@
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 #include <linux/mm.h>
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 #include <linux/delay.h>
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+#include <asm/bootinfo.h>
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 #include <asm/cacheflush.h>
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 #include <asm/page.h>
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-
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-extern const unsigned char relocate_new_kernel[];
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-extern const size_t relocate_new_kernel_size;
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-
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-extern unsigned long kexec_start_address;
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-extern unsigned long kexec_indirection_page;
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+#include <asm/uaccess.h>
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+#include "machine_kexec.h"
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 int (*_machine_kexec_prepare)(struct kimage *) = NULL;
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 void (*_machine_kexec_shutdown)(void) = NULL;
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 void (*_machine_crash_shutdown)(struct pt_regs *regs) = NULL;
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+
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 #ifdef CONFIG_SMP
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 void (*relocated_kexec_smp_wait) (void *);
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 atomic_t kexec_ready_to_reboot = ATOMIC_INIT(0);
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 #endif
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-int
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-machine_kexec_prepare(struct kimage *kimage)
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+static void machine_kexec_print_args(void)
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 {
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+	unsigned long argc = (int)kexec_args[0];
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+	int i;
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+
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+	pr_info("kexec_args[0] (argc): %lu\n", argc);
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+	pr_info("kexec_args[1] (argv): %p\n", (void *)kexec_args[1]);
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+	pr_info("kexec_args[2] (env ): %p\n", (void *)kexec_args[2]);
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+	pr_info("kexec_args[3] (desc): %p\n", (void *)kexec_args[3]);
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+
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+	for (i = 0; i < argc; i++) {
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+		pr_info("kexec_argv[%d] = %p, %s\n",
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+				i, kexec_argv[i], kexec_argv[i]);
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+	}
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+}
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+
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+static void machine_kexec_init_argv(struct kimage *image)
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+{
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+	void __user *buf = NULL;
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+	size_t bufsz;
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+	size_t size;
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+	int i;
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+
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+	bufsz = 0;
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+	for (i = 0; i < image->nr_segments; i++) {
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+		struct kexec_segment *seg;
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+
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+		seg = &image->segment[i];
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+		if (seg->bufsz < 6)
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+			continue;
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+
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+		if (strncmp((char *) seg->buf, "kexec ", 6))
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+			continue;
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+
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+		buf = seg->buf;
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+		bufsz = seg->bufsz;
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+		break;
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+	}
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+
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+	if (!buf)
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+		return;
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+
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+	size = KEXEC_COMMAND_LINE_SIZE;
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+	size = min(size, bufsz);
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+	if (size < bufsz)
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+		pr_warn("kexec command line truncated to %zd bytes\n", size);
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+
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+	/* Copy to kernel space */
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+	copy_from_user(kexec_argv_buf, buf, size);
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+	kexec_argv_buf[size - 1] = 0;
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+}
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+
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+static void machine_kexec_parse_argv(struct kimage *image)
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+{
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+	char *reboot_code_buffer;
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+	int reloc_delta;
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+	char *ptr;
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+	int argc;
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+	int i;
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+
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+	ptr = kexec_argv_buf;
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+	argc = 0;
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+
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+	/*
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+	 * convert command line string to array of parameters
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+	 * (as bootloader does).
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+	 */
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+	while (ptr && *ptr && (KEXEC_MAX_ARGC > argc)) {
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+		if (*ptr == ' ') {
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+			*ptr++ = '\0';
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+			continue;
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+		}
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+
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+		kexec_argv[argc++] = ptr;
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+		ptr = strchr(ptr, ' ');
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+	}
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+
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+	if (!argc)
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+		return;
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+
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+	kexec_args[0] = argc;
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+	kexec_args[1] = (unsigned long)kexec_argv;
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+	kexec_args[2] = 0;
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+	kexec_args[3] = 0;
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+
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+	reboot_code_buffer = page_address(image->control_code_page);
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+	reloc_delta = reboot_code_buffer - (char *)kexec_relocate_new_kernel;
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+
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+	kexec_args[1] += reloc_delta;
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+	for (i = 0; i < argc; i++)
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+		kexec_argv[i] += reloc_delta;
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+}
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+
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+int machine_kexec_prepare(struct kimage *kimage)
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+{
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+	/*
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+	 * Whenever arguments passed from kexec-tools, Init the arguments as
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+	 * the original ones to try avoiding booting failure.
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+	 */
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+
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+	kexec_args[0] = fw_arg0;
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+	kexec_args[1] = fw_arg1;
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+	kexec_args[2] = fw_arg2;
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+	kexec_args[3] = fw_arg3;
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+
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+	machine_kexec_init_argv(kimage);
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+	machine_kexec_parse_argv(kimage);
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+
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 	if (_machine_kexec_prepare)
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 		return _machine_kexec_prepare(kimage);
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 	return 0;
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 }
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-void
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-machine_kexec_cleanup(struct kimage *kimage)
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+void machine_kexec_cleanup(struct kimage *kimage)
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 {
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 }
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-void
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-machine_shutdown(void)
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+void machine_shutdown(void)
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 {
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 	if (_machine_kexec_shutdown)
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 		_machine_kexec_shutdown();
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 }
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-void
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-machine_crash_shutdown(struct pt_regs *regs)
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+void machine_crash_shutdown(struct pt_regs *regs)
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 {
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 	if (_machine_crash_shutdown)
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 		_machine_crash_shutdown(regs);
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@@ -66,10 +166,12 @@ machine_kexec(struct kimage *image)
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 	unsigned long *ptr;
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 	reboot_code_buffer =
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-	  (unsigned long)page_address(image->control_code_page);
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+		(unsigned long)page_address(image->control_code_page);
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+	pr_info("reboot_code_buffer = %p\n", (void *)reboot_code_buffer);
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 	kexec_start_address =
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 		(unsigned long) phys_to_virt(image->start);
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+	pr_info("kexec_start_address = %p\n", (void *)kexec_start_address);
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 	if (image->type == KEXEC_TYPE_DEFAULT) {
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 		kexec_indirection_page =
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@@ -77,9 +179,19 @@ machine_kexec(struct kimage *image)
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 	} else {
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 		kexec_indirection_page = (unsigned long)&image->head;
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 	}
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+	pr_info("kexec_indirection_page = %p\n", (void *)kexec_indirection_page);
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-	memcpy((void*)reboot_code_buffer, relocate_new_kernel,
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-	       relocate_new_kernel_size);
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+	pr_info("Where is memcpy: %p\n", memcpy);
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+	pr_info("kexec_relocate_new_kernel = %p, kexec_relocate_new_kernel_end = %p\n",
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+		(void *)kexec_relocate_new_kernel, &kexec_relocate_new_kernel_end);
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+	pr_info("Copy %lu bytes from %p to %p\n", KEXEC_RELOCATE_NEW_KERNEL_SIZE,
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+		(void *)kexec_relocate_new_kernel, (void *)reboot_code_buffer);
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+	memcpy((void*)reboot_code_buffer, kexec_relocate_new_kernel,
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+	       KEXEC_RELOCATE_NEW_KERNEL_SIZE);
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+
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+	pr_info("Before _print_args().\n");
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+	machine_kexec_print_args();
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+	pr_info("Before eval loop.\n");
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 	/*
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 	 * The generic kexec code builds a page list with physical
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@@ -98,15 +210,16 @@ machine_kexec(struct kimage *image)
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 	/*
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 	 * we do not want to be bothered.
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 	 */
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+	pr_info("Before irq_disable.\n");
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 	local_irq_disable();
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-	printk("Will call new kernel at %08lx\n", image->start);
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-	printk("Bye ...\n");
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+	pr_info("Will call new kernel at %08lx\n", image->start);
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+	pr_info("Bye ...\n");
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 	__flush_cache_all();
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 #ifdef CONFIG_SMP
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 	/* All secondary cpus now may jump to kexec_wait cycle */
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 	relocated_kexec_smp_wait = reboot_code_buffer +
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-		(void *)(kexec_smp_wait - relocate_new_kernel);
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+		(void *)(kexec_smp_wait - kexec_relocate_new_kernel);
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 	smp_wmb();
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 	atomic_set(&kexec_ready_to_reboot, 1);
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 #endif
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--- /dev/null
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+++ b/arch/mips/kernel/machine_kexec.h
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@@ -0,0 +1,20 @@
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+#ifndef _MACHINE_KEXEC_H
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+#define _MACHINE_KEXEC_H
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+
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+#ifndef __ASSEMBLY__
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+extern const unsigned char kexec_relocate_new_kernel[];
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+extern unsigned long kexec_relocate_new_kernel_end;
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+extern unsigned long kexec_start_address;
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+extern unsigned long kexec_indirection_page;
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+
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+extern char kexec_argv_buf[];
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+extern char *kexec_argv[];
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+
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+#define KEXEC_RELOCATE_NEW_KERNEL_SIZE	((unsigned long)&kexec_relocate_new_kernel_end - (unsigned long)kexec_relocate_new_kernel)
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+#endif /* !__ASSEMBLY__ */
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+
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+#define KEXEC_COMMAND_LINE_SIZE		256
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+#define KEXEC_ARGV_SIZE			(KEXEC_COMMAND_LINE_SIZE / 16)
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+#define KEXEC_MAX_ARGC			(KEXEC_ARGV_SIZE / sizeof(long))
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+
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+#endif
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--- a/arch/mips/kernel/relocate_kernel.S
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+++ b/arch/mips/kernel/relocate_kernel.S
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@@ -12,8 +12,9 @@
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 #include <asm/mipsregs.h>
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 #include <asm/stackframe.h>
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 #include <asm/addrspace.h>
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+#include "machine_kexec.h"
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-LEAF(relocate_new_kernel)
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+LEAF(kexec_relocate_new_kernel)
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 	PTR_L a0,	arg0
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 	PTR_L a1,	arg1
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 	PTR_L a2,	arg2
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@@ -98,7 +99,7 @@ done:
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 #endif
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 	/* jump to kexec_start_address */
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 	j		s1
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-	END(relocate_new_kernel)
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+	END(kexec_relocate_new_kernel)
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 #ifdef CONFIG_SMP
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 /*
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@@ -184,9 +185,15 @@ kexec_indirection_page:
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 	PTR		0
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 	.size		kexec_indirection_page, PTRSIZE
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-relocate_new_kernel_end:
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+kexec_argv_buf:
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+	EXPORT(kexec_argv_buf)
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+	.skip		KEXEC_COMMAND_LINE_SIZE
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+	.size		kexec_argv_buf, KEXEC_COMMAND_LINE_SIZE
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+
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+kexec_argv:
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+	EXPORT(kexec_argv)
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+	.skip		KEXEC_ARGV_SIZE
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+	.size		kexec_argv, KEXEC_ARGV_SIZE
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-relocate_new_kernel_size:
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-	EXPORT(relocate_new_kernel_size)
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-	PTR		relocate_new_kernel_end - relocate_new_kernel
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-	.size		relocate_new_kernel_size, PTRSIZE
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+kexec_relocate_new_kernel_end:
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+	EXPORT(kexec_relocate_new_kernel_end)
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