| // Structure layout of cpu registers the the bios uses. |
| // |
| // Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net> |
| // |
| // This file may be distributed under the terms of the GNU LGPLv3 license. |
| |
| #ifndef __BREGS_H |
| #define __BREGS_H |
| |
| #include "types.h" // u16 |
| #include "x86.h" // F_CF |
| |
| |
| /**************************************************************** |
| * Registers saved/restored in romlayout.S |
| ****************************************************************/ |
| |
| #define UREG(ER, R, RH, RL) union { u32 ER; struct { u16 R; u16 R ## _hi; }; struct { u8 RL; u8 RH; u8 R ## _hilo; u8 R ## _hihi; }; } |
| |
| // Layout of registers passed in to irq handlers. Note that this |
| // layout corresponds to code in romlayout.S - don't change it here |
| // without also updating the assembler code. |
| struct bregs { |
| u16 ds; |
| u16 es; |
| UREG(edi, di, di8u, di8l); |
| UREG(esi, si, si8u, si8l); |
| UREG(ebp, bp, bp8u, bp8l); |
| UREG(ebx, bx, bh, bl); |
| UREG(edx, dx, dh, dl); |
| UREG(ecx, cx, ch, cl); |
| UREG(eax, ax, ah, al); |
| struct segoff_s code; |
| u16 flags; |
| } PACKED; |
| |
| |
| /**************************************************************** |
| * Helper functions |
| ****************************************************************/ |
| |
| static inline void |
| set_cf(struct bregs *regs, int cond) |
| { |
| if (cond) |
| regs->flags |= F_CF; |
| else |
| regs->flags &= ~F_CF; |
| } |
| |
| // Frequently used return codes |
| #define RET_EUNSUPPORTED 0x86 |
| |
| static inline void |
| set_success(struct bregs *regs) |
| { |
| set_cf(regs, 0); |
| } |
| |
| static inline void |
| set_code_success(struct bregs *regs) |
| { |
| regs->ah = 0; |
| set_cf(regs, 0); |
| } |
| |
| static inline void |
| set_invalid_silent(struct bregs *regs) |
| { |
| set_cf(regs, 1); |
| } |
| |
| static inline void |
| set_code_invalid_silent(struct bregs *regs, u8 code) |
| { |
| regs->ah = code; |
| set_cf(regs, 1); |
| } |
| |
| #endif // bregs.h |