linux/arch/x86/include/asm/boot.h
H. Peter Anvin 37ba7ab5e3 x86, boot: make kernel_alignment adjustable; new bzImage fields
Make the kernel_alignment field adjustable; this allows us to set it
to a large value (intended to be 16 MB to avoid ZONE_DMA contention,
memory holes and other weirdness) while a smart bootloader can still
force a loading at a lesser alignment if absolutely necessary.

Also export pref_address (preferred loading address, corresponding to
the link-time address) and init_size, the total amount of linear
memory the kernel will require during initialization.

[ Impact: allows better kernel placement, gives bootloader more info ]

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-05-11 17:44:39 -07:00

51 lines
1.2 KiB
C

#ifndef _ASM_X86_BOOT_H
#define _ASM_X86_BOOT_H
/* Internal svga startup constants */
#define NORMAL_VGA 0xffff /* 80x25 mode */
#define EXTENDED_VGA 0xfffe /* 80x50 mode */
#define ASK_VGA 0xfffd /* ask for it at bootup */
#ifdef __KERNEL__
#include <asm/page_types.h>
/* Physical address where kernel should be loaded. */
#define LOAD_PHYSICAL_ADDR ((CONFIG_PHYSICAL_START \
+ (CONFIG_PHYSICAL_ALIGN - 1)) \
& ~(CONFIG_PHYSICAL_ALIGN - 1))
/* Minimum kernel alignment, as a power of two */
#ifdef CONFIG_x86_64
#define MIN_KERNEL_ALIGN_LG2 PMD_SHIFT
#else
#define MIN_KERNEL_ALIGN_LG2 (PAGE_SHIFT+1)
#endif
#define MIN_KERNEL_ALIGN (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2)
#if (CONFIG_PHYSICAL_ALIGN & (CONFIG_PHYSICAL_ALIGN-1)) || \
(CONFIG_PHYSICAL_ALIGN < (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2))
#error "Invalid value for CONFIG_PHYSICAL_ALIGN"
#endif
#ifdef CONFIG_KERNEL_BZIP2
#define BOOT_HEAP_SIZE 0x400000
#else /* !CONFIG_KERNEL_BZIP2 */
#ifdef CONFIG_X86_64
#define BOOT_HEAP_SIZE 0x7000
#else
#define BOOT_HEAP_SIZE 0x4000
#endif
#endif /* !CONFIG_KERNEL_BZIP2 */
#ifdef CONFIG_X86_64
#define BOOT_STACK_SIZE 0x4000
#else
#define BOOT_STACK_SIZE 0x1000
#endif
#endif /* __KERNEL__ */
#endif /* _ASM_X86_BOOT_H */