static long
vgawrite(Chan* c, void* a, long n, vlong off)
{
char *p;
ulong offset = off;
switch((ulong)c->qid.path){
case Qdir:
error(Eperm);
case Qvgactl:
if(offset || n >= READSTR)
error(Ebadarg);
p = malloc(READSTR);
if(waserror()){
free(p);
nexterror();
}
memmove(p, a, n);
p[n] = 0;
vgactl(p);
poperror();
free(p);
return n;
default:
error(Egreg);
break;
}
return 0;
}
static int32_t
vgawrite(Chan* c, void* a, int32_t n, int64_t off)
{
Proc *up = externup();
uint32_t offset = off;
Cmdbuf *cb;
VGAscr *scr;
switch((uint32_t)c->qid.path){
case Qdir:
error(Eperm);
case Qvgactl:
if(offset || n >= READSTR)
error(Ebadarg);
cb = parsecmd(a, n);
if(waserror()){
free(cb);
nexterror();
}
vgactl(cb);
poperror();
free(cb);
return n;
case Qvgaovl:
scr = &vgascreen[0];
if (scr->dev == nil || scr->dev->ovlwrite == nil) {
error(Enooverlay);
break;
}
return scr->dev->ovlwrite(scr, a, n, off);
case Qvgaovlctl:
scr = &vgascreen[0];
if (scr->dev == nil || scr->dev->ovlctl == nil) {
error(Enooverlay);
break;
}
scr->dev->ovlctl(scr, c, a, n);
return n;
default:
error(Egreg);
break;
}
return 0;
}
