#ifndef LIBKIR_H
#define LIBKIR_H
#include "realmode.h"
#ifndef ASSEMBLY
/*
* Full API documentation for these functions is in realmode.h.
*
*/
/* Access to variables in .data16 and .text16 in a way compatible with librm */
#define __data16( variable ) variable
#define __text16( variable ) variable
#define __use_data16( variable ) variable
#define __use_text16( variable ) variable
/* Copy to/from base memory */
static inline void copy_to_real_libkir ( uint16_t dest_seg, uint16_t dest_off,
void *src, size_t n ) {
__asm__ __volatile__ ( "movw %4, %%es\n\t"
"cld\n\t"
"rep movsb\n\t"
"pushw %%ds\n\t" /* restore %es */
"popw %%es\n\t"
: "=S" ( src ), "=D" ( dest_off ),
"=c" ( n ) /* clobbered */
: "S" ( src ), "r" ( dest_seg ),
"D" ( dest_off ), "c" ( n )
: "memory" );
}
static inline void copy_from_real_libkir ( void *dest,
uint16_t src_seg, uint16_t src_off,
size_t n ) {
__asm__ __volatile__ ( "movw %%ax, %%ds\n\t"
"cld\n\t"
"rep movsb\n\t"
"pushw %%es\n\t" /* restore %ds */
"popw %%ds\n\t"
: "=S" ( src_off ), "=D" ( dest ),
"=c" ( n ) /* clobbered */
: "a" ( src_seg ), "S" ( src_off ),
"D" ( dest ), "c" ( n )
: "memory" );
}
#define copy_to_real copy_to_real_libkir
#define copy_from_real copy_from_real_libkir
/*
* Transfer individual values to/from base memory. There may well be
* a neater way to do this. We have two versions: one for constant
* offsets (where the mov instruction must be of the form "mov
* %es:123, %xx") and one for non-constant offsets (where the mov
* instruction must be of the form "mov %es:(%xx), %yx". If it's
* possible to incorporate both forms into one __asm__ instruction, I
* don't know how to do it.
*
* Ideally, the mov instruction should be "mov%z0"; the "%z0" is meant
* to expand to either "b", "w" or "l" depending on the size of
* operand 0. This would remove the (minor) ambiguity in the mov
* instruction. However, gcc on at least my system barfs with an
* "internal compiler error" when confronted with %z0.
*
*/
#define put_real_kir_const_off( var, seg, off ) \
__asm__ ( "movw %w1, %%es\n\t" \
"mov %0, %%es:%c2\n\t" \
"pushw %%ds\n\t" /* restore %es */ \
"popw %%es\n\t" \
: \
: "r,r" ( var ), "rm,rm" ( seg ), "i,!r" ( off ) \
)
#define put_real_kir_nonconst_off( var, seg, off ) \
__asm__ ( "movw %w1, %%es\n\t" \
"mov %0, %%es:(%2)\n\t" \
"pushw %%ds\n\t" /* restore %es */ \
"popw %%es\n\t" \
: \
: "r" ( var ), "rm" ( seg ), "r" ( off ) \
)
#define put_real_kir( var, seg, off ) \
do { \
if ( __builtin_constant_p ( off ) ) \
put_real_kir_const_off ( var, seg, off ); \
else \
put_real_kir_nonconst_off ( var, seg, off ); \
} while ( 0 )
#define get_real_kir_const_off( var, seg, off ) \
__asm__ ( "movw %w1, %%es\n\t" \
"mov %%es:%c2, %0\n\t" \
"pushw %%ds\n\t" /* restore %es */ \
"popw %%es\n\t" \
: "=r,r" ( var ) \
: "rm,rm" ( seg ), "i,!r" ( off ) \
)
#define get_real_kir_nonconst_off( var, seg, off ) \
__asm__ ( "movw %w1, %%es\n\t" \
"mov %%es:(%2), %0\n\t" \
"pushw %%ds\n\t" /* restore %es */ \
"popw %%es\n\t" \
: "=r" ( var ) \
: "rm" ( seg ), "r" ( off ) \
)
#define get_real_kir( var, seg, off ) \
do { \
if ( __builtin_constant_p ( off ) ) \
get_real_kir_const_off ( var, seg, off ); \
else \
get_real_kir_nonconst_off ( var, seg, off ); \
} while ( 0 )
#define put_real put_real_kir
#define get_real get_real_kir
/* Place/remove parameter on real-mode stack in a way that's
* compatible with libkir
*/
#define BASEMEM_PARAMETER_INIT_LIBKIR( param ) \
( ( uint16_t ) ( ( uint32_t ) & ( param ) ) )
#define BASEMEM_PARAMETER_DONE_LIBKIR( param )
#define BASEMEM_PARAMETER_INIT BASEMEM_PARAMETER_INIT_LIBKIR
#define BASEMEM_PARAMETER_DONE BASEMEM_PARAMETER_DONE_LIBKIR
/* REAL_FRAGMENT: Declare and define a real-mode code fragment in
* .text16. We don't need this for REAL_EXEC, since we can just
* execute our real-mode code inline, but it's handy in case someone
* genuinely wants to create a block of code that can be copied to a
* specific location and then executed.
*
* Note that we put the code in the data segment, since otherwise we
* can't (easily) access it in order to copy it to its target
* location. We should never be calling any REAL_FRAGMENT routines
* directly anyway.
*/
#define REAL_FRAGMENT( name, asm_code_str ) \
extern void name ( void ); \
extern char name ## _size[]; \
__asm__ __volatile__ ( \
".section \".data.text16\"\n\t" \
".code16\n\t" \
".arch i386\n\t" \
#name ":\n\t" \
asm_code_str "\n\t" \
"lret\n\t" \
#name "_end:\n\t" \
".equ " #name "_size, " #name "_end - " #name "\n\t" \
".code16gcc\n\t" \
".previous\n\t" \
: : \
)
#define FRAGMENT_SIZE( fragment ) ( (size_t) fragment ## _size )
/* REAL_CALL: call an external real-mode routine */
#define OUT_CONSTRAINTS(...) __VA_ARGS__
#define IN_CONSTRAINTS(...) "m" ( __routine ), ## __VA_ARGS__
#define CLOBBER(...) __VA_ARGS__
#define REAL_CALL( routine, num_out_constraints, out_constraints, \
in_constraints, clobber ) \
do { \
segoff_t __routine = routine; \
__asm__ __volatile__ ( \
"pushl %" #num_out_constraints "\n\t" \
".code16\n\t" \
"pushw %%gs\n\t" /* preserve segs */ \
"pushw %%fs\n\t" \
"pushw %%es\n\t" \
"pushw %%ds\n\t" \
"pushw %%cs\n\t" /* lcall to routine */ \
"call 1f\n\t" \
"jmp 2f\n\t" \
"\n1:\n\t" \
"addr32 pushl 12(%%esp)\n\t" \
"lret\n\t" \
"\n2:\n\t" \
"popw %%ds\n\t" /* restore segs */ \
"popw %%es\n\t" \
"popw %%fs\n\t" \
"popw %%gs\n\t" \
"addw $4, %%sp\n\t" \
".code16gcc\n\t" \
: out_constraints : in_constraints : clobber \
); \
} while ( 0 )
/* REAL_EXEC: execute some inline assembly code in a way that matches
* the interface of librm
*/
#define IN_CONSTRAINTS_NO_ROUTINE( routine, ... ) __VA_ARGS__
#define REAL_EXEC( name, asm_code_str, num_out_constraints, out_constraints, \
in_constraints, clobber ) \
__asm__ __volatile__ ( \
".code16\n\t" \
"pushw %%gs\n\t" \
"pushw %%fs\n\t" \
"pushw %%es\n\t" \
"pushw %%ds\n\t" \
"\n" #name ":\n\t" \
asm_code_str \
"popw %%ds\n\t" \
"popw %%es\n\t" \
"popw %%fs\n\t" \
"popw %%gs\n\t" \
".code16gcc\n\t" \
: out_constraints \
: IN_CONSTRAINTS_NO_ROUTINE ( in_constraints ) \
: clobber \
);
#endif /* ASSEMBLY */
#endif /* LIBKIR_H */
