ia32.h

讲述linux的初始化过程

#ifndef _ASM_IA64_IA32_H
#define _ASM_IA64_IA32_H

#include <linux/config.h>

#ifdef CONFIG_IA32_SUPPORT

#include <linux/param.h>

/*
 * 32 bit structures for IA32 support.
 */

/* 32bit compatibility types */
typedef unsigned int	       __kernel_size_t32;
typedef int		       __kernel_ssize_t32;
typedef int		       __kernel_ptrdiff_t32;
typedef int		       __kernel_time_t32;
typedef int		       __kernel_clock_t32;
typedef int		       __kernel_pid_t32;
typedef unsigned short	       __kernel_ipc_pid_t32;
typedef unsigned short	       __kernel_uid_t32;
typedef unsigned short	       __kernel_gid_t32;
typedef unsigned short	       __kernel_dev_t32;
typedef unsigned int	       __kernel_ino_t32;
typedef unsigned short	       __kernel_mode_t32;
typedef unsigned short	       __kernel_umode_t32;
typedef short		       __kernel_nlink_t32;
typedef int		       __kernel_daddr_t32;
typedef int		       __kernel_off_t32;
typedef unsigned int	       __kernel_caddr_t32;
typedef long		       __kernel_loff_t32;
typedef __kernel_fsid_t	       __kernel_fsid_t32;

#define IA32_PAGE_SHIFT		12	/* 4KB pages */
#define IA32_PAGE_SIZE		(1ULL << IA32_PAGE_SHIFT)
#define IA32_CLOCKS_PER_SEC	100	/* Cast in stone for IA32 Linux */
#define IA32_TICK(tick)		((unsigned long long)(tick) * IA32_CLOCKS_PER_SEC / CLOCKS_PER_SEC)

/* fcntl.h */
struct flock32 {
       short l_type;
       short l_whence;
       __kernel_off_t32 l_start;
       __kernel_off_t32 l_len;
       __kernel_pid_t32 l_pid;
};


/* sigcontext.h */
/*
 * As documented in the iBCS2 standard..
 *
 * The first part of "struct _fpstate" is just the
 * normal i387 hardware setup, the extra "status"
 * word is used to save the coprocessor status word
 * before entering the handler.
 */
struct _fpreg_ia32 {
       unsigned short significand[4];
       unsigned short exponent;
};

struct _fpstate_ia32 {
       unsigned int    cw,
		       sw,
		       tag,
		       ipoff,
		       cssel,
		       dataoff,
		       datasel;
       struct _fpreg_ia32      _st[8];
       unsigned int    status;
};

struct sigcontext_ia32 {
       unsigned short gs, __gsh;
       unsigned short fs, __fsh;
       unsigned short es, __esh;
       unsigned short ds, __dsh;
       unsigned int edi;
       unsigned int esi;
       unsigned int ebp;
       unsigned int esp;
       unsigned int ebx;
       unsigned int edx;
       unsigned int ecx;
       unsigned int eax;
       unsigned int trapno;
       unsigned int err;
       unsigned int eip;
       unsigned short cs, __csh;
       unsigned int eflags;
       unsigned int esp_at_signal;
       unsigned short ss, __ssh;
       unsigned int fpstate;		/* really (struct _fpstate_ia32 *) */
       unsigned int oldmask;
       unsigned int cr2;
};

/* signal.h */
#define _IA32_NSIG	       64
#define _IA32_NSIG_BPW	       32
#define _IA32_NSIG_WORDS	       (_IA32_NSIG / _IA32_NSIG_BPW)

typedef struct {
       unsigned int sig[_IA32_NSIG_WORDS];
} sigset32_t;

struct sigaction32 {
       unsigned int  sa_handler;	/* Really a pointer, but need to deal 
					     with 32 bits */
       unsigned int sa_flags;
       unsigned int sa_restorer;	/* Another 32 bit pointer */
       sigset32_t sa_mask;		/* A 32 bit mask */
};

typedef unsigned int old_sigset32_t;	/* at least 32 bits */

struct old_sigaction32 {
       unsigned int  sa_handler;	/* Really a pointer, but need to deal 
					     with 32 bits */
       old_sigset32_t sa_mask;		/* A 32 bit mask */
       unsigned int sa_flags;
       unsigned int sa_restorer;	/* Another 32 bit pointer */
};

typedef struct sigaltstack_ia32 {
	unsigned int	ss_sp;
	int		ss_flags;
	unsigned int	ss_size;
} stack_ia32_t;

struct ucontext_ia32 {
	unsigned int	  uc_flags;
	unsigned int 	  uc_link;
	stack_ia32_t	  uc_stack;
	struct sigcontext_ia32 uc_mcontext;
	sigset_t	  uc_sigmask;	/* mask last for extensibility */
};

struct stat32 {
       unsigned short st_dev;
       unsigned short __pad1;
       unsigned int st_ino;
       unsigned short st_mode;
       unsigned short st_nlink;
       unsigned short st_uid;
       unsigned short st_gid;
       unsigned short st_rdev;
       unsigned short __pad2;
       unsigned int  st_size;
       unsigned int  st_blksize;
       unsigned int  st_blocks;
       unsigned int  st_atime;
       unsigned int  __unused1;
       unsigned int  st_mtime;
       unsigned int  __unused2;
       unsigned int  st_ctime;
       unsigned int  __unused3;
       unsigned int  __unused4;
       unsigned int  __unused5;
};

struct statfs32 {
       int f_type;
       int f_bsize;
       int f_blocks;
       int f_bfree;
       int f_bavail;
       int f_files;
       int f_ffree;
       __kernel_fsid_t32 f_fsid;
       int f_namelen;  /* SunOS ignores this field. */
       int f_spare[6];
};

typedef union sigval32 {
	int sival_int;
	unsigned int sival_ptr;
} sigval_t32;

typedef struct siginfo32 {
	int si_signo;
	int si_errno;
	int si_code;

	union {
		int _pad[((128/sizeof(int)) - 3)];

		/* kill() */
		struct {
			unsigned int _pid;	/* sender's pid */
			unsigned int _uid;	/* sender's uid */
		} _kill;

		/* POSIX.1b timers */
		struct {
			unsigned int _timer1;
			unsigned int _timer2;
		} _timer;

		/* POSIX.1b signals */
		struct {
			unsigned int _pid;	/* sender's pid */
			unsigned int _uid;	/* sender's uid */
			sigval_t32 _sigval;
		} _rt;

		/* SIGCHLD */
		struct {
			unsigned int _pid;	/* which child */
			unsigned int _uid;	/* sender's uid */
			int _status;		/* exit code */
			__kernel_clock_t32 _utime;
			__kernel_clock_t32 _stime;
		} _sigchld;

		/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
		struct {
			unsigned int _addr;	/* faulting insn/memory ref. */
		} _sigfault;

		/* SIGPOLL */
		struct {
			int _band;	/* POLL_IN, POLL_OUT, POLL_MSG */
			int _fd;
		} _sigpoll;
	} _sifields;
} siginfo_t32;


/*
 * IA-32 ELF specific definitions for IA-64.
 */

#define _ASM_IA64_ELF_H		/* Don't include elf.h */

#include <linux/sched.h>
#include <asm/processor.h>

/*
 * This is used to ensure we don't load something for the wrong architecture.
 */
#define elf_check_arch(x) ((x)->e_machine == EM_386)

/*
 * These are used to set parameters in the core dumps.
 */
#define ELF_CLASS	ELFCLASS32
#define ELF_DATA	ELFDATA2LSB
#define ELF_ARCH	EM_386

#define IA32_PAGE_OFFSET	0xc0000000

#define USE_ELF_CORE_DUMP
#define ELF_EXEC_PAGESIZE	IA32_PAGE_SIZE

/*
 * This is the location that an ET_DYN program is loaded if exec'ed.
 * Typical use of this is to invoke "./ld.so someprog" to test out a
 * new version of the loader.  We need to make sure that it is out of
 * the way of the program that it will "exec", and that there is
 * sufficient room for the brk.
 */
#define ELF_ET_DYN_BASE		(IA32_PAGE_OFFSET/3 + 0x1000000)

void ia64_elf32_init(struct pt_regs *regs);
#define ELF_PLAT_INIT(_r)	ia64_elf32_init(_r)

#define elf_addr_t	u32
#define elf_caddr_t	u32

/* ELF register definitions.  This is needed for core dump support.  */

#define ELF_NGREG	128			/* XXX fix me */
#define ELF_NFPREG	128			/* XXX fix me */

typedef unsigned long elf_greg_t;
typedef elf_greg_t elf_gregset_t[ELF_NGREG];

typedef struct {
	unsigned long w0;
	unsigned long w1;
} elf_fpreg_t;
typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];

/* This macro yields a bitmask that programs can use to figure out
   what instruction set this CPU supports.  */
#define ELF_HWCAP 	0

/* This macro yields a string that ld.so will use to load
   implementation specific libraries for optimization.  Not terribly
   relevant until we have real hardware to play with... */
#define ELF_PLATFORM	0

#ifdef __KERNEL__
# define SET_PERSONALITY(EX,IBCS2)				\
	(current->personality = (IBCS2) ? PER_SVR4 : PER_LINUX)
#endif

#define IA32_EFLAG	0x200

/*
 * IA-32 ELF specific definitions for IA-64.
 */
 
#define __USER_CS      0x23
#define __USER_DS      0x2B

#define SEG_LIM     32
#define SEG_TYPE    52
#define SEG_SYS     56
#define SEG_DPL     57
#define SEG_P       59
#define SEG_DB      62
#define SEG_G       63

#define FIRST_TSS_ENTRY 6
#define FIRST_LDT_ENTRY (FIRST_TSS_ENTRY+1)
#define _TSS(n) ((((unsigned long) n)<<4)+(FIRST_TSS_ENTRY<<3))
#define _LDT(n) ((((unsigned long) n)<<4)+(FIRST_LDT_ENTRY<<3))

#define IA64_SEG_DESCRIPTOR(base, limit, segtype, nonsysseg, dpl, segpresent, segdb, granularity) \
	       ((base)			       |       \
		(limit << SEG_LIM)	       |       \
		(segtype << SEG_TYPE)	       |       \
		(nonsysseg << SEG_SYS)	       |       \
		(dpl << SEG_DPL)	       |       \
		(segpresent << SEG_P)	       |       \
		(segdb << SEG_DB)	       |       \
		(granularity << SEG_G))

#define IA32_SEG_BASE 16
#define IA32_SEG_TYPE 40
#define IA32_SEG_SYS  44
#define IA32_SEG_DPL  45
#define IA32_SEG_P    47
#define IA32_SEG_HIGH_LIMIT    48
#define IA32_SEG_AVL   52
#define IA32_SEG_DB    54
#define IA32_SEG_G     55
#define IA32_SEG_HIGH_BASE 56

#define IA32_SEG_DESCRIPTOR(base, limit, segtype, nonsysseg, dpl, segpresent, avl, segdb, granularity) \
	       ((limit & 0xFFFF)			       |       \
		 (base & 0xFFFFFF << IA32_SEG_BASE)	       |       \
		(segtype << IA32_SEG_TYPE)		       |       \
		(nonsysseg << IA32_SEG_SYS)		       |       \
		(dpl << IA32_SEG_DPL)			       |       \
		(segpresent << IA32_SEG_P)		       |       \
		(((limit >> 16) & 0xF) << IA32_SEG_HIGH_LIMIT) |       \
		(avl << IA32_SEG_AVL)			       |       \
		(segdb << IA32_SEG_DB)			       |       \
		(granularity << IA32_SEG_G)		       |       \
		(((base >> 24) & 0xFF) << IA32_SEG_HIGH_BASE)) 

#define IA32_IOBASE    0x2000000000000000 /* Virtual addres for I/O space */

#define IA32_CR0       0x80000001      /* Enable PG and PE bits */
#define IA32_CR4       0	       /* No architectural extensions */

/*
 *  IA32 floating point control registers starting values
 */

#define IA32_FSR_DEFAULT	0x55550000		/* set all tag bits */
#define IA32_FCR_DEFAULT	0x17800000037fULL	/* extended precision, all masks */

#define IA32_PTRACE_GETREGS	12
#define IA32_PTRACE_SETREGS	13
#define IA32_PTRACE_GETFPREGS	14
#define IA32_PTRACE_SETFPREGS	15

#define ia32_start_thread(regs,new_ip,new_sp) do {				\
	set_fs(USER_DS);							\
	ia64_psr(regs)->cpl = 3;	/* set user mode */			\
	ia64_psr(regs)->ri = 0;		/* clear return slot number */		\
	ia64_psr(regs)->is = 1;		/* IA-32 instruction set */		\
	regs->cr_iip = new_ip;							\
	regs->r12 = new_sp;							\
	regs->ar_rnat = 0;							\
	regs->loadrs = 0;							\
} while (0)

extern void ia32_gdt_init (void);
extern int ia32_setup_frame1 (int sig, struct k_sigaction *ka, siginfo_t *info,
			       sigset_t *set, struct pt_regs *regs);
extern void ia32_init_addr_space (struct pt_regs *regs);
extern int ia32_setup_arg_pages (struct linux_binprm *bprm);
extern int ia32_exception (struct pt_regs *regs, unsigned long isr);

#endif /* !CONFIG_IA32_SUPPORT */
 
#endif /* _ASM_IA64_IA32_H */