minix/include/arch/i386/include/stackframe.h
Ben Gras d65f6f7009 imported code harmonisation
. common/include/arch/i386 is not actually an imported
	  sys/arch/i386/include but leftover Minix files;
	  remove and move to include/
	. move include/ufs to sys/ufs, where it came from, now that
	  we have a sys/ hierarchy
	. move mdocml/ to external/bsd/, now we have that
	. single sys/arch/i386/stand/ import for boot stuff
2012-03-14 16:02:59 +01:00

37 lines
1.6 KiB
C

#ifndef STACK_FRAME_H
#define STACK_FRAME_H
typedef unsigned reg_t; /* machine register */
typedef reg_t segdesc_t;
/* The stack frame layout is determined by the software, but for efficiency
* it is laid out so the assembly code to use it is as simple as possible.
* 80286 protected mode and all real modes use the same frame, built with
* 16-bit registers. Real mode lacks an automatic stack switch, so little
* is lost by using the 286 frame for it. The 386 frame differs only in
* having 32-bit registers and more segment registers. The same names are
* used for the larger registers to avoid differences in the code.
*/
struct stackframe_s {
u16_t gs; /* last item pushed by save */
u16_t fs; /* ^ */
u16_t es; /* | */
u16_t ds; /* | */
reg_t di; /* di through cx are not accessed in C */
reg_t si; /* order is to match pusha/popa */
reg_t fp; /* bp */
reg_t st; /* hole for another copy of sp */
reg_t bx; /* | */
reg_t dx; /* | */
reg_t cx; /* | */
reg_t retreg; /* ax and above are all pushed by save */
reg_t retadr; /* return address for assembly code save() */
reg_t pc; /* ^ last item pushed by interrupt */
reg_t cs; /* | */
reg_t psw; /* | */
reg_t sp; /* | */
reg_t ss; /* these are pushed by CPU during interrupt */
};
#endif /* #ifndef STACK_FRAME_H */