From c9ffa12af29ecb40ed6cde680139a28dbf5322cd Mon Sep 17 00:00:00 2001
From: Divyam Khandelwal <divyam@Divyams-MacBook-Pro.local>
Date: Sat, 28 Apr 2018 21:49:38 -0500
Subject: [PATCH] RTC virtualised
---
student-distrib/rtc.c | 131 ++++++++++++++++++++++++++----------------
student-distrib/rtc.h | 9 ++-
2 files changed, 91 insertions(+), 49 deletions(-)
diff --git a/student-distrib/rtc.c b/student-distrib/rtc.c
index 0de20a0..9e92193 100644
--- a/student-distrib/rtc.c
+++ b/student-distrib/rtc.c
@@ -1,8 +1,13 @@
#include "rtc.h"
/* Set interrupt flag */
-//interrupt_flag = 1;
+interrupt_flag = 1;
+/* For virtualisation */
+rtc_active[MAX_TERMINAL] = {0,0,0};
+rtc_flag[MAX_TERMINAL] = {1,1,1};
+rtc_counter[MAX_TERMINAL] = {0,0,0};
+rtc_init_counter[MAX_TERMINAL] = {0,0,0};
/* rtc_init()
* Inputs: void
@@ -14,7 +19,7 @@ void rtc_init(void)
{
uint8_t prev;
- //int32_t freq;
+ // int32_t freq;
/* select register B, and disable NMI */
outb(DISABLE_NMI_B, RTC_PORT);
@@ -26,6 +31,9 @@ void rtc_init(void)
outb(prev | BIT_SIX, RTC_DATA);
/* Enable interrupts */
+ // freq = 2;
+ // rtc_write(NULL, &freq, 4);
+
enable_irq(RTC_IRQ);
}
@@ -39,12 +47,26 @@ void rtc_init(void)
*/
void rtc_interrupt(void)
{
+ int i;
+
/* logic to enable more than one RTC interrupt */
outb(0x0C, 0x70); /* 0x0C = DATA to write, 0x70 = port */
inb(0x71); /* read from port 0x71 (RTC Data port) */
/* Clear interrupt flag */
- interrupt_flag = 0;
+ for (i = 0; i < MAX_TERMINAL; i++)
+ {
+ rtc_counter[i]--;
+ /* Check if counter has reached zero */
+ if(rtc_counter[i] == 0)
+ {
+ /* Clear interrupt flag */
+ rtc_flag[i] = 0;
+ /* Reset counter */
+ rtc_counter[i] = rtc_init_counter[i];
+ }
+ }
+ // interrupt_flag = 0;
return;
}
@@ -58,11 +80,15 @@ void rtc_interrupt(void)
*/
int32_t rtc_read(int32_t fd, void* buf, int32_t nbytes)
{
+
/* Set flag */
- interrupt_flag = 1;
+ rtc_flag[running_terminal] = 1;
+ //interrupt_flag = 1;
+ sti();
/* Wait until interrupt handler clears flag */
- while (interrupt_flag);
+ while (rtc_flag[running_terminal]);
+ cli();
return 0;
}
@@ -103,37 +129,41 @@ int32_t rtc_write(int32_t fd, const void* buf, int32_t nbytes)
if (valid_freq != 1)
return -1;
- /* Translate frequency to rate */
+ rtc_counter[running_terminal] = INIT_FREQ/freq;
- temp_freq = freq;
+ rtc_init_counter[running_terminal] = rtc_counter[running_terminal];
- for (i = 1; i <= MAX_FREQ_POW; i++)
- {
- temp_freq = temp_freq >> 1;
+ // /* Translate frequency to rate */
- if ((temp_freq & bit_mask) == 1)
- {
- rate = RATE_OFFSET - i;
- break;
- }
- //temp_freq = temp_freq >> 1;
- }
+ // temp_freq = freq;
- /* Set the rate */
- rate &= 0x0F;
+ // for (i = 1; i <= MAX_FREQ_POW; i++)
+ // {
+ // temp_freq = temp_freq >> 1;
- /* Disable interrupts */
- cli();
- /* set index to register A, disable NMI */
- outb(DISABLE_NMI_A, RTC_PORT);
- /* get initial value of register A */
- prev = inb(RTC_DATA);
- /* reset index to A */
- outb(DISABLE_NMI_A, RTC_PORT);
- /* write only our rate to A. Note, rate is the bottom 4 bits. */
- outb((prev & 0xF0) | rate, RTC_DATA);
- /* Enable interrupts */
- sti();
+ // if ((temp_freq & bit_mask) == 1)
+ // {
+ // rate = RATE_OFFSET - i;
+ // break;
+ // }
+ // //temp_freq = temp_freq >> 1;
+ // }
+
+ // /* Set the rate */
+ // rate &= 0x0F;
+
+ // /* Disable interrupts */
+ // cli();
+ // /* set index to register A, disable NMI */
+ // outb(DISABLE_NMI_A, RTC_PORT);
+ // /* get initial value of register A */
+ // prev = inb(RTC_DATA);
+ // /* reset index to A */
+ // outb(DISABLE_NMI_A, RTC_PORT);
+ // /* write only our rate to A. Note, rate is the bottom 4 bits. */
+ // outb((prev & 0xF0) | rate, RTC_DATA);
+ // /* Enable interrupts */
+ // sti();
/* Return number of bytes written */
return FOUR_BYTES;
@@ -146,26 +176,31 @@ int32_t rtc_write(int32_t fd, const void* buf, int32_t nbytes)
*/
int32_t rtc_open(const uint8_t* filename)
{
- uint8_t rate, prev;
+ /* Set RTC to active for the running terminal */
+ rtc_active[running_terminal] = 1;
+ return 0;
- /* Set the frequency to 2 Hz */
- rate = TWO_HZ;
- rate &= 0x0F;
- /* Disable interrupts */
- cli();
- /* set index to register A, disable NMI */
- outb(DISABLE_NMI_A, RTC_PORT);
- /* get initial value of register A */
- prev = inb(RTC_DATA);
- /* reset index to A */
- outb(DISABLE_NMI_A, RTC_PORT);
- /* write only our rate to A. Note, rate is the bottom 4 bits. */
- outb((prev & 0xF0) | rate, RTC_DATA);
- /* Enable interrupts */
- sti();
+ // uint8_t rate, prev;
+
+ // /* Set the frequency to 2 Hz */
+ // rate = TWO_HZ;
+ // rate &= 0x0F;
+
+ // /* Disable interrupts */
+ // cli();
+ // /* set index to register A, disable NMI */
+ // outb(DISABLE_NMI_A, RTC_PORT);
+ // /* get initial value of register A */
+ // prev = inb(RTC_DATA);
+ // /* reset index to A */
+ // outb(DISABLE_NMI_A, RTC_PORT);
+ // /* write only our rate to A. Note, rate is the bottom 4 bits. */
+ // outb((prev & 0xF0) | rate, RTC_DATA);
+ // /* Enable interrupts */
+ // sti();
- return 0;
+ // return 0;
}
/* rtc_close()
diff --git a/student-distrib/rtc.h b/student-distrib/rtc.h
index 13b55a7..1fc3020 100644
--- a/student-distrib/rtc.h
+++ b/student-distrib/rtc.h
@@ -16,6 +16,7 @@
#define BIT_SIX 0x40
#define TWO_HZ 15
#define FREQ_MAX 8192
+#define INIT_FREQ 1024
#define MAX_FREQ_POW 13
#define RATE_OFFSET 16
#define FOUR_BYTES 4
@@ -28,7 +29,13 @@
#define REGISTER_C 0x0C
/* Interrupt flag for read() */
-volatile int interrupt_flag;
+extern int interrupt_flag;
+
+/* Global Variables for Virtualization */
+extern int rtc_active[MAX_TERMINAL];
+extern int rtc_flag[MAX_TERMINAL];
+extern int rtc_counter[MAX_TERMINAL];
+
/*
* rtc_init()
--
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