/**
* Remaps the PIC.
*
* Initially, in real mode, the first 32 positions of the IDT are occupied by the exceptions
* and the PIC's interrupts, IRQs. This function moves the IRQs in the IDT, so they
* don't overlap with the exceptions.
*
* @param offset1 The offset of the position where the IRQ0 was.
* @param offset2 The offset of the position where the IRQ0 will be moved.
*/
void reMapPIC(int offset1,int offset2){
unsigned char mask1,mask2;
// Saving masks
mask1 = inB(PIC1_DATA);
mask2 = inB(PIC2_DATA);
// Starting initialization
outB(PIC1_COMMAND,0x11);
outB(PIC2_COMMAND,0x11);
// Setting PIC offset
outB(PIC1_DATA,offset1);
outB(PIC2_DATA,offset2);
// Continuing initialization
outB(PIC1_DATA,4);
outB(PIC2_DATA,2);
outB(PIC1_DATA,ICW4_8086);
outB(PIC2_DATA,ICW4_8086);
// Restore masks
outB(PIC1_DATA,mask1);
outB(PIC2_DATA,mask2);
}
/**
* Read the registers from the Real Time Clock.
*
* It reads the registers from the RTC and stores the data in the struct which
* pointer it receives. It handles the different types of format in which the data
* is stored in the RTC registers.
*
* @param regs Pointer to struct where the data from RTC registers will be stored.
*
*/
void readRTCRegisters(RTCRegisters *regs){
int format;
// Getting format register
outB(RTCADDRESS, 11);
format = inB(RTCDATA);
// Getting seconds
regs->seconds = readSeconds();
// Getting minutes
regs->minutes = readMinutes();
// Getting hours (value may be 12hs o 24hs format)
regs->hours = readHours();
// Getting day of the month
regs->day = readDay();
// Getting month
regs->month = readMonth();
// Getting year
regs->year = readYear();
// Getting century
regs->century = readCentury();
// If in BCD mode, convert to binary
if ((format & 0x02) == 0x02 ) {
regs->seconds = BCDTOBINARY(regs->seconds);
regs->minutes = BCDTOBINARY( regs->minutes);
regs->hours = BCDTOBINARY(regs->hours);
regs->day = BCDTOBINARY(regs->day );
regs->month = BCDTOBINARY(regs->month);
regs->year = BCDTOBINARY(regs->year);
regs->century = BCDTOBINARY(regs->century);
}
// If in 12 hs mode, convert to 24 hs mode
if ((format & 0x04) == 0x04) {
// Masking off the pm/am bit
if ( (regs->hours & 0x80) == 0x80 ) {
regs->hours &= 0x7F;
// Setting 12 pm as 0 regs->hours and adjusting the rest
regs->hours = (regs->hours == 12)? 0 : regs->hours + 12;
}
}
}
/**
* Read the RTC century register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readCentury(void) {
outB(RTCADDRESS, CENTURYREGISTER);
return inB(RTCDATA);
}
/**
* Read the RTC year register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readYear(void) {
outB(RTCADDRESS, YEARREGISTER);
return inB(RTCDATA);
}
/**
* Read the RTC month register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readMonth(void) {
outB(RTCADDRESS, MONTHREGISTER);
return inB(RTCDATA);
}
/**
* Read the RTC day of the month register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readDay(void) {
outB(RTCADDRESS, DAYREGISTER);
return inB(RTCDATA);
}
/**
* Read the RTC hours register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readHours(void) {
outB(RTCADDRESS, HOURSREGISTER);
return inB(RTCDATA);
}
/**
* Read the RTC minutes register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readMinutes(void) {
outB(RTCADDRESS, MINUTESREGISTER);
return inB(RTCDATA);
}
/**
* Read the RTC seconds register.
*
* @return An integer representing the data stored in the register (different formats).
*/
int readSeconds(void) {
outB(RTCADDRESS, SECONDSREGISTER);
return inB(RTCDATA);
}
