diff options
| author |   Vivek Goyal <vgoyal@in.ibm.com> | 2007-05-10 22:22:15 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-11 08:29:32 -0700 |
| commit | 069f11f9d66bc582fb40a37a7b92363f5d321969 (patch) | |
| tree | 70d07076d1026fedfeaa9a4cdf04ba1b3cf9aad6 /include/asm-x86_64/page.h | |
| parent | i386: work around miscompilation of alternatives code (diff) | |
| download | linux-dev-069f11f9d66bc582fb40a37a7b92363f5d321969.tar.xz linux-dev-069f11f9d66bc582fb40a37a7b92363f5d321969.zip | |
x86_64: display more intuitive error message if kernel is not 2MB aligned
o x86_64 kernel needs to be compiled for 2MB aligned addresses. Currently
we are using BUILD_BUG_ON() to warn the user if he has not done so. But
looks like folks are not finding message very intutive and don't open
the respective c file to find problem source. (Bug 8439)
arch/x86_64/kernel/head64.c: In function 'x86_64_start_kernel':
arch/x86_64/kernel/head64.c:70: error: size of array 'type name' is negative
o Using preprocessor directive #error to print a better message if
CONFIG_PHYSICAL_START is not aligned to 2MB boundary.
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-x86_64/page.h')
| -rw-r--r-- | include/asm-x86_64/page.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/asm-x86_64/page.h b/include/asm-x86_64/page.h index dee632fa457d..e327c830da0c 100644 --- a/include/asm-x86_64/page.h +++ b/include/asm-x86_64/page.h @@ -80,6 +80,15 @@ extern unsigned long phys_base; #define __PHYSICAL_START CONFIG_PHYSICAL_START #define __KERNEL_ALIGN 0x200000 +/* + * Make sure kernel is aligned to 2MB address. Catching it at compile + * time is better. Change your config file and compile the kernel + * for a 2MB aligned address (CONFIG_PHYSICAL_START) + */ +#if (CONFIG_PHYSICAL_START % __KERNEL_ALIGN) != 0 +#error "CONFIG_PHYSICAL_START must be a multiple of 2MB" +#endif + #define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START) #define __START_KERNEL_map _AC(0xffffffff80000000, UL) #define __PAGE_OFFSET _AC(0xffff810000000000, UL) |