diff --git a/student-distrib/lib.c b/student-distrib/lib.c
index b0cb78d7972f89f97be2068b2e527360462a7f54..e757d7fd6165c17e8b3442a423a7b2e87c8e0907 100644
--- a/student-distrib/lib.c
+++ b/student-distrib/lib.c
@@ -34,6 +34,9 @@ void update_cursor(int32_t term_id)
{
term_id = visible_terminal;
uint16_t position = terminal[term_id].terminal_y * NUM_COLS + terminal[term_id].terminal_x;
+
+ //HEX values copied from https://wiki.osdev.org/Text_Mode_Cursor
+
outb(0x0F, 0x3D4);
outb((uint8_t)(position&0xFF), 0x3D5);
outb(0x0E, 0x3D4);
diff --git a/student-distrib/proc.c b/student-distrib/proc.c
index b8792dc2aa369eff0fe7989d0027e2ff4765c22d..2fcf4cbfa8037188f5ac9171a1b02dc342cf0671 100644
--- a/student-distrib/proc.c
+++ b/student-distrib/proc.c
@@ -34,9 +34,8 @@ void control_initilization(void)
total_prog_count = 0;
visible_terminal = 0;
- running_terminal = 0;
+ running_terminal = 1; // initialized to 1 so we end in the first shell
cur_pid = 0;
- counter = 0;
}
/* The file descriptor table checking function
@@ -198,7 +197,7 @@ int32_t parse_cmd(const uint8_t* command, uint8_t* parsed_cmd, uint8_t (*argv)[M
/* copy command to parsed_cmd */
for (i = 0; i < (end - start); i++)
- if(command[i+start] != 0x0D) //check for \n
+ if(command[i+start] != 0x0D) //0x0D = \n
parsed_cmd[i] = command[i+start];
command_length = strlen((int8_t*)command);
@@ -236,7 +235,7 @@ int32_t parse_cmd(const uint8_t* command, uint8_t* parsed_cmd, uint8_t (*argv)[M
/* copy argument to return array */
for (i = 0; i < (end - start); i++)
- if(command[i+start] != 0x0D) //check for \n
+ if(command[i+start] != 0x0D) //0x0D = \n
argv[j][i] = command[i+start];
}
diff --git a/student-distrib/rtc.c b/student-distrib/rtc.c
index c99778c333c90245f468372aa3b37b742aae27cd..063167bc3f619c5c7eea183730051a30a300d944 100644
--- a/student-distrib/rtc.c
+++ b/student-distrib/rtc.c
@@ -80,9 +80,9 @@ void rtc_interrupt(void)
*/
int32_t rtc_read(int32_t fd, void* buf, int32_t nbytes)
{
-
/* Set flag */
- rtc_flag[running_terminal] = 1;
+ if(rtc_active[running_terminal] == 1)
+ rtc_flag[running_terminal] = 1;
sti();
@@ -130,38 +130,6 @@ int32_t rtc_write(int32_t fd, const void* buf, int32_t nbytes)
rtc_init_counter[running_terminal] = rtc_counter[running_terminal];
- // /* Translate frequency to rate */
-
- // temp_freq = freq;
-
- // for (i = 1; i <= MAX_FREQ_POW; i++)
- // {
- // temp_freq = temp_freq >> 1;
-
- // 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;
}
@@ -183,38 +151,16 @@ int32_t rtc_open(const uint8_t* filename)
rtc_init_counter[running_terminal] = rtc_counter[running_terminal];
return 0;
-
-
- // 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;
}
/* rtc_close()
- * Inputs: fd - file descriptor
+ * Inputs: fd - file descriptor
* Return Value: returns 0
- * Function: *Not virtualized yet*
+ * Function: *Not virtualized yet*
*/
int32_t rtc_close(int32_t fd)
{
- /* Not virtualised yet */
+ rtc_active[running_terminal] = 0;
return 0;
}
diff --git a/student-distrib/scheduler.c b/student-distrib/scheduler.c
index a2cf7019df20a4dca2dd4ee84c021b813b0e0f98..89861d143c8d4f98b874bd7ec25a11ea2843f1b8 100644
--- a/student-distrib/scheduler.c
+++ b/student-distrib/scheduler.c
@@ -2,14 +2,17 @@
/* The scheduler function
*
- * DISCRIPTION: This function switch running process every 15 ms
- *
+ * DESCRIPTION: This function switch running process every 15 ms
+ * Input: NONE
+ * Output: NONE
+ * Side Effects: switches processes
*/
void scheduler(void){
- // Bookkeeping
+ // get current pcb
pcb_t * curr_pcb = terminal[running_terminal].pcb;
+ // check if no program is running on that terminal
if(curr_pcb == NULL)
{
@@ -18,6 +21,7 @@ void scheduler(void){
pcb_t pcb;
pcb.scheduler_flag = 1;
+ //move esp and ebp to pcb
asm volatile(
"movl %%esp, %0 \n"
"movl %%ebp, %1 \n"
@@ -26,17 +30,22 @@ void scheduler(void){
: "memory"
);
+ // set pointer to terminal pcb
terminal[running_terminal].pcb = &pcb;
+ // perform terminal switch to the next terminal
switch_terminal(running_terminal);
- printf("terminal = %d\n", running_terminal);
+ printf("terminal = %d\n", running_terminal+1);
+ // send PIT eoi now because we don't return here after execute
send_eoi(PIT_IRQ);
+ // start shell
execute((uint8_t *)"shell");
}
+ // save esp and ebp of old process
asm volatile(
"movl %%esp, %0 \n"
"movl %%ebp, %1 \n"
@@ -46,34 +55,42 @@ void scheduler(void){
);
// Round Robin
- running_terminal = (running_terminal + 1) % 3;
+ running_terminal = (running_terminal + 1) % MAX_TERMINAL;
+ // check again for non initialized pcb
if(terminal[running_terminal].pcb == NULL)
{
send_eoi(PIT_IRQ);
return;
}
+ // remap video memory
remap_vidmem();
+
+ // adjust memory for terminals
store_vid_mem(running_terminal);
+ // get next process
pcb_t* next_pcb = terminal[running_terminal].pcb;
// update current pid, tss and remap paging
remap_proc(next_pcb->pid);
+ // store kernel stack segment and esp
tss.ss0 = KERNEL_DS;
tss.esp0 = _8_MB - _8_KB * (next_pcb->pid);
+ // send PIT eoi now because we don't return here
send_eoi(PIT_IRQ);
+ // perform process switch by changing esp and ebp
asm volatile(
- //change esp and ebp
"movl %0, %%esp \n"
"movl %1, %%ebp \n"
:
: "r" (next_pcb->current_esp), "r" (next_pcb->current_ebp)
: "esp" , "ebp"
);
- // printf("[SCHEDULE] after ebp and esp breaking");
+
+ return;
}
diff --git a/student-distrib/syscall.c b/student-distrib/syscall.c
index 30b9d1873fd40e7619169ab6081d3070e42ddff8..142bf7cf56e95c8c7d23595fe88bc988cdc851e3 100644
--- a/student-distrib/syscall.c
+++ b/student-distrib/syscall.c
@@ -21,6 +21,7 @@ int32_t halt (uint8_t status) {
/* set all present flags in PCB to "Not In Use" */
for (i = 0; i < MAX_FILE_NUM; i++)
{
+ // close all files for current pcb
if( i > 1 && pcb_cur->fd[i].flags == 1 )
close(i);
@@ -452,9 +453,9 @@ int32_t vidmap (uint8_t** screen_start)
remap_vidmem();
- *screen_start = (uint8_t *)(0x8400000); // 132MB, video memory starting address
+ *screen_start = (uint8_t *)(_132_MB); // 132MB, video memory starting address
- return 0x8400000;
+ return _132_MB;
}
/*
diff --git a/student-distrib/types.h b/student-distrib/types.h
index 110fb31005a3c28061d45d28e5501360e0285169..a78a8cdc555bf0e9a911cd754f366dab3a353751 100644
--- a/student-distrib/types.h
+++ b/student-distrib/types.h
@@ -141,25 +141,24 @@ typedef struct file_object {
/* Process control block structure */
typedef struct pcb {
- file_object_t fd[MAX_FILE_NUM]; /* File descriptor array */
+ file_object_t fd[MAX_FILE_NUM]; /* File descriptor array */
- int32_t shell_flag;
- int32_t scheduler_flag;
+ int32_t shell_flag; /* indicates if pcb is shell */
+ int32_t scheduler_flag; /* overrides esp and ebp setting in pcb_init */
- uint32_t pid; /* Holds current process ID */
- uint32_t current_esp; /* Store Current esp for scheduling */
- uint32_t current_ebp; /* Store Current ebp for scheduling */
- uint32_t current_eip; /* Store Current eip for scheduling */
+ uint32_t pid; /* Holds current process ID */
+ uint32_t current_esp; /* Store Current esp for scheduling */
+ uint32_t current_ebp; /* Store Current ebp for scheduling */
struct pcb* parent_pcb;
- uint32_t parent_pid; /* Holds parent process ID */
- uint32_t parent_esp; /* Stores Kernel ESP, EBP*/
- uint32_t parent_ebp; /* Stores Kernel ESP, EBP*/
-
- uint32_t tss_esp0; /* saves TSS before context switch */
-
- uint32_t arg_num; /* Number of arguments in argv */
- uint8_t cmd[MAX_COMMAND_SIZE]; /* Command */
+ uint32_t parent_pid; /* Holds parent process ID */
+ uint32_t parent_esp; /* Stores Kernel ESP, EBP*/
+ uint32_t parent_ebp; /* Stores Kernel ESP, EBP*/
+
+ uint32_t tss_esp0; /* saves TSS before context switch */
+
+ uint32_t arg_num; /* Number of arguments in argv */
+ uint8_t cmd[MAX_COMMAND_SIZE]; /* Command */
uint8_t argv[MAX_ARGUMENT_NUM][MAX_ARGUMENT_SIZE]; /* Argument table */
} pcb_t;
@@ -184,7 +183,6 @@ volatile int32_t buffer_index;
/*---------------------------- Global variable -------------------------------*/
uint32_t filesys_start; /* Starting place for file system */
- int32_t counter; /* */
terminal_t terminal[MAX_TERMINAL]; /* Terminal array that store the information for each termianl */
int32_t visible_terminal; /* */