Added comments and cleanup

6 files changed, 27 insertions, 15 deletions

diff --git a/src/cpu/irq.c b/src/cpu/irq.c
index 442c834..125c3a6 100644
--- a/src/cpu/irq.c
+++ b/src/cpu/irq.c
@@ -15,10 +15,15 @@ void handle_data(unsigned char);
 void c_irq_handler(void)
 {
 	unsigned long source = load32(CORE0_IRQ_SOURCE);
+	// Check if GPU Interrupt
 	if (source & (1 << 8)) {
+		// Check if UART Interrupt
 		if(load32(IRQ_PENDING2) & (1 << 25)) {
+			// Check if UART Interrupt is Masked
 			if(load32(UART0_MIS) & (1<<4)) {
+				// Get the UART data
 				unsigned long data = load32(UART0_DR);
+				// Draw it on the screen
 				{
 					unsigned int x = g_Drawer.x;
 					unsigned int y = g_Drawer.y;
@@ -29,6 +34,7 @@ void c_irq_handler(void)
 					g_Drawer.y = y;
 				}
 
+				// Handle the recieved data
 				// Ctrl+T to toggle timer
 				if(data == 0x14) {
 					unsigned long timer_status;
@@ -50,19 +56,25 @@ void c_irq_handler(void)
 					}
 					g_Drawer.x = x;
 					g_Drawer.y = y;
-				} else {
+				}
+				// Add task to handle the data
+				else {
 					add_thread(handle_data, (void*)data, 1);
 				}
 				return;
 			}
-		} else if (*(unsigned long*)SYS_TIMER_CS == SYS_TIMER_SC_M0) {
+		}
+		// Check if System Time Compare 0 Triggered the Interrupt
+		else if (*(unsigned long*)SYS_TIMER_CS == SYS_TIMER_SC_M0) {
 			volatile unsigned long* timer_cs = (unsigned long*)SYS_TIMER_CS;
 			volatile unsigned long* timer_chi = (unsigned long*)SYS_TIMER_CHI;
 			volatile unsigned long* nexttime = (unsigned long*)SYS_TIMER_C0;
 			*timer_cs = SYS_TIMER_SC_M0;
 			*nexttime = *timer_chi + 60000000;
 		}
-	} else if (source & (1 << 3)) {
+	}
+	// Check if CNTV triggered the interrupt
+	else if (source & (1 << 3)) {
 		c_timer();
 		return;
 	}
@@ -73,6 +85,7 @@ static unsigned long counter = 0;
 unsigned long c_fiq_handler(void)
 {
 	unsigned long source = load32(CORE0_FIQ_SOURCE);
+	// Check if CNTV triggered the interrupt
 	if (source & (1 << 3)) {
 		c_timer();
 		counter++;
diff --git a/src/drivers/uart.c b/src/drivers/uart.c
index 41ce10e..d6bb92b 100644
--- a/src/drivers/uart.c
+++ b/src/drivers/uart.c
@@ -5,7 +5,7 @@
 #include <sys/schedule.h>
 #include <symbols.h>
 
-#define UART_BUFFER_SIZE 0x100
+#define UART_BUFFER_SIZE 0x400
 struct UartBuffer {
 	char buffer[UART_BUFFER_SIZE];
 	unsigned long roffset;
@@ -52,7 +52,8 @@ void* uart_print(char* s)
 		ubuffer.woffset %= UART_BUFFER_SIZE;
 		ptr += 1;
 	}
-	add_thread(uart_flush, 0, 5);
+	// Low priority flush run whenever
+	add_thread(uart_flush, 0, PRIORITIES-1);
 	return 0;
 }
 
diff --git a/src/exceptions/svc.S b/src/exceptions/svc.S
index cffa09c..c23df82 100644
--- a/src/exceptions/svc.S
+++ b/src/exceptions/svc.S
@@ -82,6 +82,3 @@ svc_000005: // Release Lock
 	b svc_exit
 svc_exit:
 	ldmfd sp!, {r0-r12,pc}^
-
-.section .data
-svc_msg:	.asciz "SVC Handler #"
diff --git a/src/sys/kernel.S b/src/sys/kernel.S
index 90e1c4f..3ffc6a5 100644
--- a/src/sys/kernel.S
+++ b/src/sys/kernel.S
@@ -4,10 +4,7 @@
 kernel_main:
 	///https://wiki.osdev.org/ARM_Paging
 	// Query the ID_MMFR0 register
-	mrc p15, 0, r2, c0, c1, 4
-	mov r0, #0
-	mov r1, #7
-	bl draw_hex32
+	mrc p15, 0, r0, c0, c1, 4
 	bl sysinit
 	// Intentional undefined instruction
 	// .word 0xf7f0a000
diff --git a/src/sys/schedule.c b/src/sys/schedule.c
index dd59891..347b91a 100644
--- a/src/sys/schedule.c
+++ b/src/sys/schedule.c
@@ -42,8 +42,10 @@ void init_scheduler(void)
 struct RStack get_stack(void)
 {
 	struct RStack r = {.sp = 0, .idx = -1};
+	// Find an available stack
 	for (int i = 0; i < MAX_THREADS; i++) {
 		if (stacks_table[i] == 0) {
+			// Mark unavailable
 			stacks_table[i] = 1;
 			r.idx = i;
 			r.sp = (void*)0x20000000 - STACK_SIZE*i;
diff --git a/src/util/status.c b/src/util/status.c
index 614581e..1d3894b 100644
--- a/src/util/status.c
+++ b/src/util/status.c
@@ -100,6 +100,7 @@ void status(void)
 		write_string(&g_Drawer, " BGR");
 	}
 
+	// Core Stacks
 	g_Drawer.x = 0;
 	g_Drawer.y = 5;
 	write_string(&g_Drawer, "SVC      IRQ      FIQ      User/SYS\n");
@@ -107,7 +108,6 @@ void status(void)
 		write_char(&g_Drawer, ' ');
 	g_Drawer.x = 0;
 	g_Drawer.y = 6;
-
 	unsigned long sp = (unsigned long)getsvcstack();
 	write_hex32(&g_Drawer, sp);
 	write_char(&g_Drawer, ' ');
@@ -120,12 +120,16 @@ void status(void)
 	sp = (unsigned long)getsysstack();
 	write_hex32(&g_Drawer, sp);
 	write_char(&g_Drawer, '\n');
+
+	// Report Core that updated status
 	unsigned long coren;
 	asm volatile (
 		"mrc p15, #0, %0, c0, c0, #5\n"
 		"and %0, %0, #3" : "=r"(coren) :: "cc");
 	write_string(&g_Drawer, "Status Updated by Core #");
 	write_10(&g_Drawer, coren);
+
+	// Report Sys Timer Stataus
 	write_string(&g_Drawer, "\nSys Timer Status ");
 	coren = *(volatile unsigned long*)SYS_TIMER_CS;
 	write_10(&g_Drawer, coren);
@@ -142,6 +146,4 @@ void status(void)
 
 	g_Drawer.x = x;
 	g_Drawer.y = y;
-
-	draw_stacks();
 }