source: bootcd/isolinux/syslinux-6.03/gpxe/src/arch/i386/include/setjmp.h

#ifndef ETHERBOOT_SETJMP_H
#define ETHERBOOT_SETJMP_H

FILE_LICENCE ( GPL2_OR_LATER );

#include <stdint.h>
#include <realmode.h>

/** A jump buffer */
typedef struct {
        uint32_t retaddr;
        uint32_t ebx;
        uint32_t esp;
        uint32_t ebp;
        uint32_t esi;
        uint32_t edi;
} jmp_buf[1];

/** A real-mode-extended jump buffer */
typedef struct {
        jmp_buf env;
        uint16_t rm_ss;
        uint16_t rm_sp;
} rmjmp_buf[1];

extern int __asmcall setjmp ( jmp_buf env );
extern void __asmcall longjmp ( jmp_buf env, int val );

#define rmsetjmp( _env ) ( {                    \
        (_env)->rm_ss = rm_ss;                  \
        (_env)->rm_sp = rm_sp;                  \
        setjmp ( (_env)->env ); } )             \

#define rmlongjmp( _env, _val ) do {            \
        rm_ss = (_env)->rm_ss;                  \
        rm_sp = (_env)->rm_sp;                  \
        longjmp ( (_env)->env, (_val) );        \
        } while ( 0 )

#endif /* ETHERBOOT_SETJMP_H */