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authorEric W. Biederman <ebiederm@xmission.com>2005-06-25 14:57:49 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-06-25 16:24:48 -0700
commit3d345e3fc9e9177deb7c82e5c79e32d77eb63cce (patch)
tree4c9ecef7b3baf0f9649933510d2645a50665c2d6 /arch
parent5ded01e83ec3b60191b03b9f88f53acd4e6112f5 (diff)
[PATCH] kexec: x86: add CONFIG_PYSICAL_START
For one kernel to report a crash another kernel has created we need to have 2 kernels loaded simultaneously in memory. To accomplish this the two kernels need to built to run at different physical addresses. This patch adds the CONFIG_PHYSICAL_START option to the x86 kernel so we can do just that. You need to know what you are doing and the ramifications are before changing this value, and most users won't care so I have made it depend on CONFIG_EMBEDDED bzImage kernels will work and run at a different address when compiled with this option but they will still load at 1MB. If you need a kernel loaded at a different address as well you need to boot a vmlinux. Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/Kconfig11
-rw-r--r--arch/i386/boot/compressed/head.S7
-rw-r--r--arch/i386/boot/compressed/misc.c7
-rw-r--r--arch/i386/kernel/vmlinux.lds.S2
4 files changed, 20 insertions, 7 deletions
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index 961ab20032f..31567f4d333 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -942,6 +942,17 @@ config SECCOMP
source kernel/Kconfig.hz
+config PHYSICAL_START
+ hex "Physical address where the kernel is loaded" if EMBEDDED
+ default "0x100000"
+ help
+ This gives the physical address where the kernel is loaded.
+ Primarily used in the case of kexec on panic where the
+ fail safe kernel needs to run at a different address than
+ the panic-ed kernel.
+
+ Don't change this unless you know what you are doing.
+
endmenu
diff --git a/arch/i386/boot/compressed/head.S b/arch/i386/boot/compressed/head.S
index c5e80b69e7d..b5893e4ecd3 100644
--- a/arch/i386/boot/compressed/head.S
+++ b/arch/i386/boot/compressed/head.S
@@ -25,6 +25,7 @@
#include <linux/linkage.h>
#include <asm/segment.h>
+#include <asm/page.h>
.globl startup_32
@@ -74,7 +75,7 @@ startup_32:
popl %esi # discard address
popl %esi # real mode pointer
xorl %ebx,%ebx
- ljmp $(__BOOT_CS), $0x100000
+ ljmp $(__BOOT_CS), $__PHYSICAL_START
/*
* We come here, if we were loaded high.
@@ -99,7 +100,7 @@ startup_32:
popl %ecx # lcount
popl %edx # high_buffer_start
popl %eax # hcount
- movl $0x100000,%edi
+ movl $__PHYSICAL_START,%edi
cli # make sure we don't get interrupted
ljmp $(__BOOT_CS), $0x1000 # and jump to the move routine
@@ -124,5 +125,5 @@ move_routine_start:
movsl
movl %ebx,%esi # Restore setup pointer
xorl %ebx,%ebx
- ljmp $(__BOOT_CS), $0x100000
+ ljmp $(__BOOT_CS), $__PHYSICAL_START
move_routine_end:
diff --git a/arch/i386/boot/compressed/misc.c b/arch/i386/boot/compressed/misc.c
index cedc55cc47d..e1330766965 100644
--- a/arch/i386/boot/compressed/misc.c
+++ b/arch/i386/boot/compressed/misc.c
@@ -13,6 +13,7 @@
#include <linux/vmalloc.h>
#include <linux/tty.h>
#include <asm/io.h>
+#include <asm/page.h>
/*
* gzip declarations
@@ -308,7 +309,7 @@ static void setup_normal_output_buffer(void)
#else
if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < 1024) error("Less than 2MB of memory");
#endif
- output_data = (char *)0x100000; /* Points to 1M */
+ output_data = (char *)__PHYSICAL_START; /* Normally Points to 1M */
free_mem_end_ptr = (long)real_mode;
}
@@ -333,8 +334,8 @@ static void setup_output_buffer_if_we_run_high(struct moveparams *mv)
low_buffer_size = low_buffer_end - LOW_BUFFER_START;
high_loaded = 1;
free_mem_end_ptr = (long)high_buffer_start;
- if ( (0x100000 + low_buffer_size) > ((ulg)high_buffer_start)) {
- high_buffer_start = (uch *)(0x100000 + low_buffer_size);
+ if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) {
+ high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size);
mv->hcount = 0; /* say: we need not to move high_buffer */
}
else mv->hcount = -1;
diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S
index e17ab69c1f0..7e01a528a83 100644
--- a/arch/i386/kernel/vmlinux.lds.S
+++ b/arch/i386/kernel/vmlinux.lds.S
@@ -14,7 +14,7 @@ ENTRY(phys_startup_32)
jiffies = jiffies_64;
SECTIONS
{
- . = LOAD_OFFSET + 0x100000;
+ . = __KERNEL_START;
phys_startup_32 = startup_32 - LOAD_OFFSET;
/* read-only */
_text = .; /* Text and read-only data */