From: Michael Gernoth <michael@gernoth.net>
Date: Tue, 24 May 2011 22:29:31 +0000 (+0200)
Subject: parse System.map for memory locations
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/ms2-kexec/commitdiff_plain/4f8bca6642175fb93e3830028e31519f50f8323f?ds=inline

parse System.map for memory locations

This removes static memory addresses of sys_call_table and
kernel_restart_prepare and makes it easier to compile for a
new target
---

diff --git a/Makefile b/Makefile
index aea8202..544acff 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,10 @@ ARCH=arm
 CROSS_COMPILE=arm-eabi-
 CROSS_PATH=$(PWD)/../prebuilt/linux-x86/toolchain/arm-eabi-4.4.0/bin
 
-EXTRA_CFLAGS += -DCONFIG_KEXEC -Wall
+SYS_CALL_TABLE := $(shell grep ' T sys_call_table$$' $(KDIR)/System.map | cut -f1 -d' ')
+KERNEL_RESTART_PREPARE := $(shell grep ' T kernel_restart_prepare$$' $(KDIR)/System.map | cut -f1 -d' ')
+
+EXTRA_CFLAGS += -DCONFIG_KEXEC -Wall -DSYS_CALL_TABLE=0x$(SYS_CALL_TABLE) -DKERNEL_RESTART_PREPARE=0x$(KERNEL_RESTART_PREPARE)
 
 obj-m += kexec_load.o
 kexec_load-objs := kexec.o machine_kexec.o mmu.o sys.o core.o relocate_kernel.o \
diff --git a/kexec.c b/kexec.c
index 2f98d32..1efad11 100644
--- a/kexec.c
+++ b/kexec.c
@@ -1457,6 +1457,7 @@ unsigned long **find_sys_call_table(void)  {
 
 static int __init kexec_module_init(void)
 {
+#if 0
 	sys_call_table=(void **)find_sys_call_table();
 	if(sys_call_table==NULL) {
 		printk(KERN_ERR "Cannot find the system call address\n"); 
@@ -1464,9 +1465,9 @@ static int __init kexec_module_init(void)
 	}
 
 	printk(KERN_INFO "kexec: Found sys_call_table at: %p\n", sys_call_table);
+#endif
 
-	//sys_call_table=(void **)0xc003d004;
-	sys_call_table=(void **)0xc00350c4;
+	sys_call_table=(void **)SYS_CALL_TABLE;
 	printk(KERN_INFO "kexec: Force sys_call_table at: %p\n", sys_call_table);
 
 	/* Set kexec_load() syscall. */
diff --git a/sys.c b/sys.c
index fd71e4f..e631609 100644
--- a/sys.c
+++ b/sys.c
@@ -59,8 +59,7 @@ BLOCKING_NOTIFIER_HEAD(notifier_head);
 
 void kernel_restart_prepare(char *cmd)
 {
-#warning assuming kernel_restart_prepare is at 0xc00779cc
-	void (*original_kernel_restart_prepare)(char *) = (void (*)(char *))0xc00779cc;
+	void (*original_kernel_restart_prepare)(char *) = (void (*)(char *))KERNEL_RESTART_PREPARE;
 	return original_kernel_restart_prepare(cmd);
 #if 0
 	register_reboot_notifier(&dummy_notifier_reboot);