void fork()
{
struct Task* task = malloc(sizeof(struct Task));
if(!task)
panic("Task alloc failed!");
memcpy(task, current_task, sizeof(struct Task));
task->segment = task_seg;
task_seg += 0x1000;
farmemcpy(0x0000, 0x0000, 0x8000, task->segment, current_task->segment);
farmemcpy(0x8000, 0x8000, 0x8000, task->segment, current_task->segment);
memsetw(task->stack, 0, KERNEL_STACK_WORDS);
/* create a kernel stack for returning to userspace */
task->stack[KERNEL_STACK_WORDS - 1] = &kernel_exit; /* return address */
task->stack[KERNEL_STACK_WORDS - 2] = 0x0000; /* bp */
task->stack[KERNEL_STACK_WORDS - 3] = 0x0000; /* ax */
task->stack[KERNEL_STACK_WORDS - 4] = 0x0000; /* si */
task->stack[KERNEL_STACK_WORDS - 5] = 0x0000; /* di */
task->kernel_sp = &task->stack[KERNEL_STACK_WORDS - 5];
task->stack_top = &task->stack[KERNEL_STACK_WORDS - 1];
pokew(task->segment, task->user_sp + 18, task->segment);
pokew(task->segment, task->user_sp + 12, 0);
task->next = task_list;
task_list = task;
return;
}
/*
* Bios Keyboard Poll
*/
static void kbd_timer(int __data)
{
int dav;
#if 0
static int clk[4] = {0x072D, 0x075C, 0x077C, 0x072F,};
static int c = 0;
pokew(0xB800, (79+0*80)*2, clk[(c++)&0x03]);
#endif
#asm
jmp nhp
savekey:
xor ah,ah
int 0x16
push ax
call _AddQueue
pop ax
nhp:
mov ah, #0x01
int 0x16
xor ah,ah
cmp al,#6
jge savekey
#endasm
restart_timer();
}
void VGASetTextMode(uint8_t high_res) {
uint8_t font_height = 0;
if(high_res) {
VGAWriteRegisters(vga_text_90_60);
vga_text_width = 90;
vga_text_height = 60;
font_height = 8;
} else {
VGAWriteRegisters(vga_text_80_25);
vga_text_width = 80;
vga_text_height = 25;
font_height = 16;
}
/* Set font. */
if(font_height >= 16) {
VGAWriteFont(vga_8x16_font, 16);
} else {
VGAWriteFont(vga_8x8_font, 8);
}
/* tell the BIOS what we've done, so BIOS text output works OK */
pokew(0x40, 0x4A, vga_text_width); /* columns on screen */
pokew(0x40, 0x4C, vga_text_width * vga_text_height * 2); /* framebuffer size */
pokew(0x40, 0x50, 0); /* cursor pos'n */
pokeb(0x40, 0x60, font_height - 1); /* cursor shape */
pokeb(0x40, 0x61, font_height - 2);
pokeb(0x40, 0x84, vga_text_height - 1); /* rows on screen - 1 */
pokeb(0x40, 0x85, font_height); /* char height */
/* Set white-on-black for all text. */
for(size_t i = 0; i < vga_text_width * vga_text_height; i++) {
pokeb(0xB800, i * 2 + 1, 7);
}
}
void env_delete(word segm)
{ DBG_ENTER("env_delete", Suppl_env)
DBG_ARGUMENTS( ("env=%u", segm) )
chkMem
unless_segm(segm)
DBG_EXIT
DBG_ARGUMENTS( ("effective env=%u", segm) )
pokew(SEG2MCB(segm), MCB_OFF_OWNER, _psp);
freeBlk(segm);
chkMem
/* Make sure the deleted segment won't be referenced */
env_relocateSegment(segm, 0);
DBG_EXIT
}
int env_nullStrings(word segm)
{ word ofs;
DBG_ENTER("env_nullStrings", Suppl_env)
DBG_ARGUMENTS( ("env=%u", segm) )
chkMem
unless_segm(segm)
DBG_RETURN_I( ESUPPL_NOENV)
DBG_ARGUMENTS( ("effective env=%u", segm) )
ofs = env_endOfVars(segm) + 1; /* offset of string counter word */
if(mcb_length(segm) - 2 <= ofs)
DBG_RETURN_I( ESUPPL_NOMEM)
pokew(segm, ofs, 0);
chkMem
DBG_RETURN_I( ESUPPL_OK)
}
void task_set_register(struct Task* task, unsigned int reg, unsigned int value)
{
pokew(task->segment, task->user_sp + reg, value);
}
void put_ustack(register struct task_struct *t,int off,int val)
{
pokew(t->t_regs.ss, t->t_regs.sp+off, (__u16) val);
}
