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/* -*- linux-c -*- ------------------------------------------------------- *
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright 2007 rPath, Inc. - All Rights Reserved
* Copyright 2009 Intel Corporation; author H. Peter Anvin
*
* This file is part of the Linux kernel, and is made available under
* the terms of the GNU General Public License version 2.
*
* ----------------------------------------------------------------------- */
/**
* @file
* @brief Main declarations for the real mode code
*/
#ifndef BOOT_BOOT_H
#define BOOT_BOOT_H
#define STACK_SIZE 512 /* Minimum number of bytes for stack */
/** Carry flag */
#define X86_EFLAGS_CF 0x00000001
/** PE flag */
#define X86_CR0_PE 0x00000001
#ifndef __ASSEMBLY__
#include <types.h>
/* we are still in real mode here! */
#define THIS_IS_REALMODE_CODE asm(".code16gcc");
struct biosregs {
union {
struct {
uint32_t edi;
uint32_t esi;
uint32_t ebp;
uint32_t _esp;
uint32_t ebx;
uint32_t edx;
uint32_t ecx;
uint32_t eax;
uint32_t _fsgs;
uint32_t _dses;
uint32_t eflags;
};
struct {
uint16_t di, hdi;
uint16_t si, hsi;
uint16_t bp, hbp;
uint16_t _sp, _hsp;
uint16_t bx, hbx;
uint16_t dx, hdx;
uint16_t cx, hcx;
uint16_t ax, hax;
uint16_t gs, fs;
uint16_t es, ds;
uint16_t flags, hflags;
};
struct {
uint8_t dil, dih, edi2, edi3;
uint8_t sil, sih, esi2, esi3;
uint8_t bpl, bph, ebp2, ebp3;
uint8_t _spl, _sph, _esp2, _esp3;
uint8_t bl, bh, ebx2, ebx3;
uint8_t dl, dh, edx2, edx3;
uint8_t cl, ch, ecx2, ecx3;
uint8_t al, ah, eax2, eax3;
};
};
};
/* functions in the realmode part */
extern int enable_a20(void);
extern void initregs(struct biosregs *regs);
extern void intcall(uint8_t int_no, const struct biosregs *ireg, struct biosregs *oreg);
extern void boot_puts(char*);
extern void __attribute__((noreturn)) die(void);
extern void __attribute__((noreturn)) protected_mode_jump(void);
struct gdt_ptr {
uint16_t len;
uint32_t ptr;
} __attribute__((packed));
/* These functions are used to reference data in other segments. */
static inline uint16_t ds(void)
{
uint16_t seg;
asm("movw %%ds,%0" : "=rm" (seg));
return seg;
}
static inline void set_fs(uint16_t seg)
{
asm volatile("movw %0,%%fs" : : "rm" (seg));
}
static inline uint16_t fs(void)
{
uint16_t seg;
asm volatile("movw %%fs,%0" : "=rm" (seg));
return seg;
}
static inline void set_gs(uint16_t seg)
{
asm volatile("movw %0,%%gs" : : "rm" (seg));
}
static inline uint16_t gs(void)
{
uint16_t seg;
asm volatile("movw %%gs,%0" : "=rm" (seg));
return seg;
}
typedef unsigned int addr_t;
static inline uint8_t rdfs8(addr_t addr)
{
uint8_t v;
asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*(uint8_t *)addr));
return v;
}
static inline uint16_t rdfs16(addr_t addr)
{
uint16_t v;
asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*(uint16_t *)addr));
return v;
}
static inline uint32_t rdfs32(addr_t addr)
{
uint32_t v;
asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*(uint32_t *)addr));
return v;
}
static inline void wrfs8(uint8_t v, addr_t addr)
{
asm volatile("movb %1,%%fs:%0" : "+m" (*(uint8_t *)addr) : "qi" (v));
}
static inline void wrfs16(uint16_t v, addr_t addr)
{
asm volatile("movw %1,%%fs:%0" : "+m" (*(uint16_t *)addr) : "ri" (v));
}
static inline void wrfs32(uint32_t v, addr_t addr)
{
asm volatile("movl %1,%%fs:%0" : "+m" (*(uint32_t *)addr) : "ri" (v));
}
static inline uint8_t rdgs8(addr_t addr)
{
uint8_t v;
asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*(uint8_t *)addr));
return v;
}
static inline uint16_t rdgs16(addr_t addr)
{
uint16_t v;
asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*(uint16_t *)addr));
return v;
}
static inline uint32_t rdgs32(addr_t addr)
{
uint32_t v;
asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*(uint32_t *)addr));
return v;
}
static inline void wrgs8(uint8_t v, addr_t addr)
{
asm volatile("movb %1,%%gs:%0" : "+m" (*(uint8_t *)addr) : "qi" (v));
}
static inline void wrgs16(uint16_t v, addr_t addr)
{
asm volatile("movw %1,%%gs:%0" : "+m" (*(uint16_t *)addr) : "ri" (v));
}
static inline void wrgs32(uint32_t v, addr_t addr)
{
asm volatile("movl %1,%%gs:%0" : "+m" (*(uint32_t *)addr) : "ri" (v));
}
/** use the built in memset function for the real mode code */
#define memset(d,c,l) __builtin_memset(d,c,l)
#endif /* __ASSEMBLY__ */
#endif /* BOOT_BOOT_H */
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