From e69f202d0a1419219198566e1c22218a5c71a9a6 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Thu, 7 Dec 2006 02:14:04 +0100 Subject: [PATCH] i386: Implement CONFIG_PHYSICAL_ALIGN o Now CONFIG_PHYSICAL_START is being replaced with CONFIG_PHYSICAL_ALIGN. Hardcoding the kernel physical start value creates a problem in relocatable kernel context due to boot loader limitations. For ex, if somebody compiles a relocatable kernel to be run from address 4MB, but this kernel will run from location 1MB as grub loads the kernel at physical address 1MB. Kernel thinks that I am a relocatable kernel and I should run from the address I have been loaded at. So somebody wanting to run kernel from 4MB alignment location (for improved performance regions) can't do that. o Hence, Eric proposed that probably CONFIG_PHYSICAL_ALIGN will make more sense in relocatable kernel context. At run time kernel will move itself to a physical addr location which meets user specified alignment restrictions. Signed-off-by: Vivek Goyal Signed-off-by: Andi Kleen --- include/asm-i386/boot.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/asm-i386') diff --git a/include/asm-i386/boot.h b/include/asm-i386/boot.h index 96b228e6e79..8ce79a6fa89 100644 --- a/include/asm-i386/boot.h +++ b/include/asm-i386/boot.h @@ -12,4 +12,8 @@ #define EXTENDED_VGA 0xfffe /* 80x50 mode */ #define ASK_VGA 0xfffd /* ask for it at bootup */ -#endif +/* Physical address where kenrel should be loaded. */ +#define LOAD_PHYSICAL_ADDR ((0x100000 + CONFIG_PHYSICAL_ALIGN - 1) \ + & ~(CONFIG_PHYSICAL_ALIGN - 1)) + +#endif /* _LINUX_BOOT_H */ -- cgit v1.2.3