/* where NUM is an IRQ number. For the PC, interrupts can be intercepted simply with "irq_intercept_in ioapic" (note that IRQ0 comes out with NUM=0 even though it is remapped to GSI 2).  */
static int hex2nib(char ch)
/* where NUM is an IRQ number. For the PC, interrupts can be intercepted simply with "irq_intercept_in ioapic" (note that IRQ0 comes out with NUM=0 even though it is remapped to GSI 2).  */
static int hex2nib(char ch)
{
    if (ch >= '0' && ch <= '9') {
        return ch - '0';
    } else if (ch >= 'a' && ch <= 'f') {
        return 10 + (ch - 'a');
    } else if (ch >= 'A' && ch <= 'F') {
        return 10 + (ch - 'a');
    } else {
        return -1;
    }
}