linux/include/asm-x86/setup.h

#ifndef _ASM_X86_SETUP_H
#define _ASM_X86_SETUP_H

#define COMMAND_LINE_SIZE 2048

#ifndef __ASSEMBLY__

/* Interrupt control for vSMPowered x86_64 systems */
void vsmp_init(void);

/* Crashkernel reservation */
void reserve_crashkernel(void);

#ifndef CONFIG_PARAVIRT
#define paravirt_post_allocator_init()	do {} while (0)
#endif
#endif /* __ASSEMBLY__ */

#ifdef __KERNEL__

#ifdef __i386__

#include <linux/pfn.h>
/*
 * Reserved space for vmalloc and iomap - defined in asm/page.h
 */
#define MAXMEM_PFN	PFN_DOWN(MAXMEM)
#define MAX_NONPAE_PFN	(1 << 20)

#endif /* __i386__ */

#define PARAM_SIZE 4096		/* sizeof(struct boot_params) */

#define OLD_CL_MAGIC		0xA33F
#define OLD_CL_ADDRESS		0x020	/* Relative to real mode data */
#define NEW_CL_POINTER		0x228	/* Relative to real mode data */

#ifndef __ASSEMBLY__
#include <asm/bootparam.h>

#ifndef _SETUP

/*
 * This is set up by the setup-routine at boot-time
 */
extern struct boot_params boot_params;

/*
 * Do NOT EVER look at the BIOS memory size location.
 * It does not work on many machines.
 */
#define LOWMEMSIZE()	(0x9f000)

#ifdef __i386__

void __init i386_start_kernel(void);

extern unsigned long init_pg_tables_start;
extern unsigned long init_pg_tables_end;

#endif /* __i386__ */
#endif /* _SETUP */
#endif /* __ASSEMBLY__ */
#endif  /*  __KERNEL__  */

#endif /* _ASM_X86_SETUP_H */