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kernel
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sys.com compiled with ia16-elf-gcc: fill in missing functions.

This commit is contained in:
Bart Oldeman 2017-12-21 12:35:47 -05:00 committed by Kenneth J Davis
parent 89d97b18de
commit 9e04932d2b
2 changed files with 53 additions and 2 deletions
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2
mkfiles/gcc.mak
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@ -17,7 +17,7 @@ LIBPLUS=
LIBTERM=
TINY=-mcmodel=tiny
CFLAGST=-w -o $@
CFLAGST=-Os -fpack-struct -fcall-used-es -w -o $@
CFLAGSC=
TARGET=KGC

53
sys/sys.c
View File

@ -120,31 +120,73 @@ struct _diskfree_t {
int int86(int ivec, union REGS *in, union REGS *out)
{
/* must save sp for int25/26 */
asm("mov %5, (1f+1); jmp 0f; 0:mov %%di, %%dx; mov %%sp, %%di;"
"1:int $0x00; mov %%di, %%sp; sbb %0, %0" :
"=r"(out->x.cflag),
"=a"(out->x.ax), "=b"(out->x.bx), "=c"(out->x.cx), "=d"(out->x.dx) :
"q"((unsigned char)ivec), "a"(in->x.ax), "b"(in->x.bx),
"c"(in->x.cx), "D"(in->x.dx), "S"(in->x.si) :
"cc", "memory");
return out->x.ax;
}
int intdos(union REGS *in, union REGS *out)
{
return int86(0x21, in, out);
}
int intdosx(union REGS *in, union REGS *out, struct SREGS *s)
{
asm("push %%ds; mov %%bx, %%ds; int $0x21; pop %%ds; sbb %0, %0":
"=r"(out->x.cflag), "=a"(out->x.ax) :
"a"(in->x.ax), "c"(in->x.cx), "d"(in->x.dx),
"D"(in->x.di), "S"(in->x.si), "b"(s->ds), "e"(s->es) :
"cc", "memory");
return out->x.ax;
}
unsigned _dos_allocmem(unsigned size, unsigned *seg)
{
union REGS in, out;
in.h.ah = 0x48;
in.x.bx = size;
unsigned ret = intdos(&in, &out);
if (!out.x.cflag)
{
*seg = ret;
ret = 0;
}
return ret;
}
unsigned _dos_freemem(unsigned seg)
{
union REGS in, out;
struct SREGS s;
in.h.ah = 0x49;
s.es = seg;
return intdosx(&in, &out, &s);
}
unsigned int _dos_getdiskfree(unsigned int drive,
struct diskfree_t *diskspace)
struct _diskfree_t *diskspace)
{
union REGS in, out;
in.x.ax = 0x3600;
in.x.dx = drive;
unsigned ret = intdos(&in, &out);
diskspace->avail_clusters = out.x.bx;
diskspace->sectors_per_cluster = out.x.dx;
diskspace->bytes_per_sector = out.x.cx;
return ret;
}
long filelength(int fhandle)
{
long ret = lseek(fhandle, 0, SEEK_END);
lseek(fhandle, 0, SEEK_SET);
return ret;
}
struct find_t {
@ -162,6 +204,15 @@ struct find_t {
int _dos_findfirst(const char *file_name, unsigned int attr,
struct find_t *find_tbuf)
{
union REGS in, out;
in.h.ah = 0x4e;
in.x.dx = FP_OFF(file_name);
in.x.cx = attr;
intdos(&in, &out);
if (out.x.cflag)
return out.x.ax;
memcpy(find_tbuf, (void *)0x80, sizeof(*find_tbuf));
return 0;
}
#else
#include <io.h>