source: buchla-68k/include/setjmp.h

/*
   =============================================================================
        setjmp.h -- header for setjmp() and longjmp() functions
        Version 1 -- 1987-06-11 -- D.N. Lynx Crowe

        Registers a0 and d0 are assumed to be scratch registers,
        and are not saved by these functions.

        Register d0 is usually used as the return value register.
        Exception:  Motorola C uses a0 for the return value if it's a pointer.

        This is true of most C compilers for the 68000, including:
        Digital Research / Alcyon, Lattice, Aztec / Manx, Greenhills, Motorola.
   =============================================================================
*/

#pragma once

#include "stdint.h"

struct  JMP_BUF {       /* setjmp() / longjmp() environment structure */

        int32_t jmpret;         /* return address */

        int32_t jmp_d1;         /* data registers */
        int32_t jmp_d2;
        int32_t jmp_d3;
        int32_t jmp_d4;
        int32_t jmp_d5;
        int32_t jmp_d6;
        int32_t jmp_d7;

        int32_t jmp_a1;         /* address registers */
        int32_t jmp_a2;
        int32_t jmp_a3;
        int32_t jmp_a4;
        int32_t jmp_a5;
        int32_t jmp_a6;
        int32_t jmp_a7;
};

typedef struct JMP_BUF jmp_buf;