newlib-cygwin/newlib/libc/sys/go32/go32func.c

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2000-02-18 03:39:52 +08:00
#include <sys/types.h>
#include "go32.h"
#include "dpmi.h"
#include "dos.h"
u_short _go32_my_cs()
{
asm("movw %cs,%ax");
}
u_short _go32_my_ds()
{
asm("movw %ds,%ax");
}
u_short _go32_my_ss()
{
asm("movw %ss,%ax");
}
u_short _go32_conventional_mem_selector()
{
return _go32_info_block.selector_for_linear_memory;
}
static _go32_dpmi_registers regs;
static volatile u_long ctrl_break_count = 0;
static int ctrl_break_hooked = 0;
static _go32_dpmi_seginfo old_vector;
static _go32_dpmi_seginfo new_vector;
static ctrl_break_isr(_go32_dpmi_registers *regs)
{
ctrl_break_count ++;
}
u_long _go32_was_ctrl_break_hit()
{
u_long cnt;
_go32_want_ctrl_break(1);
cnt = ctrl_break_count;
ctrl_break_count = 0;
return cnt;
}
void _go32_want_ctrl_break(int yes)
{
if (yes)
{
if (ctrl_break_hooked)
return;
_go32_dpmi_get_real_mode_interrupt_vector(0x1b, &old_vector);
new_vector.pm_offset = (int)ctrl_break_isr;
_go32_dpmi_allocate_real_mode_callback_iret(&new_vector, &regs);
_go32_dpmi_set_real_mode_interrupt_vector(0x1b, &new_vector);
ctrl_break_count = 0;
ctrl_break_hooked = 1;
}
else
{
if (!ctrl_break_hooked)
return;
_go32_dpmi_set_real_mode_interrupt_vector(0x1b, &old_vector);
_go32_dpmi_free_real_mode_callback(&new_vector);
ctrl_break_count = 0;
ctrl_break_hooked = 0;
}
}