fix interrupt enabling/disabling/polling and uart fifo setting to make the io work properly

6 files changed, 24 insertions, 20 deletions

diff --git a/PL0_test.c b/PL0_test.c
index fed62a2..0bfebc7 100644
--- a/PL0_test.c
+++ b/PL0_test.c
@@ -8,8 +8,6 @@ void PL0_main(void)
   puts("Hello userspace! Type 'f' if you want me to try accessing "
        "kernel memory!");
 
-
-  asm volatile("mov r0, #17\n\rsvc #0" ::: "r0");
   while (1)
     {
       char c = getchar();
diff --git a/armclock.h b/armclock.h
index 2b2aec9..f81f363 100644
--- a/armclock.h
+++ b/armclock.h
@@ -46,11 +46,21 @@ static inline void armclk_init(void)
 
 static inline void armclk_enable_timer_irq(void)
 {
+  armclk_control_t ctrl =
+    (armclk_control_t) *(uint32_t volatile*) ARMCLK_CONTROL;
+  ctrl.fields.interrupt_enable = 1;
+  *(uint32_t volatile*) ARMCLK_CONTROL = ctrl.raw;
+  
   *(uint32_t volatile*) ARM_ENABLE_BASIC_IRQS = 1;
 }
 
 static inline void armclk_disable_timer_irq(void)
 {
+  armclk_control_t ctrl =
+    (armclk_control_t) *(uint32_t volatile*) ARMCLK_CONTROL;
+  ctrl.fields.interrupt_enable = 0;
+  *(uint32_t volatile*) ARMCLK_CONTROL = ctrl.raw;
+  
   *(uint32_t volatile*) ARM_DISABLE_BASIC_IRQS = 1;
 }
 
@@ -62,7 +72,7 @@ static inline void armclk_irq_settimeout(uint32_t timeout)
 
 static inline _Bool armclk_irq_pending(void)
 {
-  return *(uint32_t volatile*) ARMCLK_RAW_IRQ;
+  return *(uint32_t volatile*) ARM_IRQ_BASIC_PENDING & 1;
 }
 
 #endif // ARMCLOCK_H
diff --git a/interrupts.c b/interrupts.c
index 9beee0a..bf7ed02 100644
--- a/interrupts.c
+++ b/interrupts.c
@@ -18,7 +18,7 @@ void undefined_instruction_vector(void)
 {
   error("Undefined instruction occured");
 }
-_Bool flag = 0;
+
 uint32_t supervisor_call_handler(uint32_t regs[14])
 {
   switch(regs[0]) {
@@ -38,15 +38,6 @@ uint32_t supervisor_call_handler(uint32_t regs[14])
   case UART_WRITE:
     error("UART_WRITE not implemented!!!!!");
     break;
-  case 17:
-    {
-      flag = 1;
-      /* while (1) */
-      /* 	{ */
-      /* 	  printbin(*(uint32_t volatile*) PL011_UART_MIS); puts(""); */
-      /* 	} */
-      break;
-    }
   default:
     // perhaps we should kill the process now?
     error("unknown supervisor call type!!!!!");
diff --git a/scheduler.c b/scheduler.c
index 3399bf4..141ba1d 100644
--- a/scheduler.c
+++ b/scheduler.c
@@ -113,7 +113,6 @@ schedule_save_context(uint32_t regs[14])
 
   schedule();
 }
-extern _Bool flag;
 
 void __attribute__((noreturn)) schedule(void)
 {
@@ -126,7 +125,6 @@ void __attribute__((noreturn)) schedule(void)
       new_CPSR.fields.PSR_IRQ_MASK_BIT = 0;
   
       write_CPSR(new_CPSR);
-      if (flag) putchar('l');
       
       asm volatile("wfi");
 
@@ -146,8 +144,8 @@ void __attribute__((noreturn)) schedule(void)
   	       [stackaddr]"r" (PL0_sp),
   	       [linkaddr]"r" (PL0_lr) : "memory");
 
-  armclk_enable_timer_irq();
   armclk_irq_settimeout(0x00100000);
+  armclk_enable_timer_irq();
 
   write_SPSR(PL0_PSR);
   
diff --git a/uart.c b/uart.c
index c9fcd35..c4ae445 100644
--- a/uart.c
+++ b/uart.c
@@ -52,11 +52,14 @@ void uart_init()
   // Fractional part register = (.627 * 64) + 0.5 = 40.6 = ~40.
   mmio_write(PL011_UART_FBRD, 40);
 
-  // Enable FIFO & 8 bit data transmission (1 stop bit, no parity).
-  mmio_write(PL011_UART_LCRH, (1 << 4) | (1 << 5) | (1 << 6));
+  // Set 8 bit data transmission (1 stop bit, no parity)
+  // and disable FIFO to be able to receive interrupt every received
+  // char, not every 2 chars
+  mmio_write(PL011_UART_LCRH, (1 << 5) | (1 << 6));
 
   // set interrupt to come when transmit FIFO becomes ≤ 1/8 full
   // or receive FIFO becomes ≥ 1/8 full
+  // (not really matters, since we disabled FIFOs)
   mmio_write(PL011_UART_IFLS, 0);
 
   // Enable PL011_UART, receive & transfer part of UART.2
@@ -64,6 +67,10 @@ void uart_init()
 
   // At first, it's probably safer to disable interrupts :)
   uart_irq_disable();
+
+  // That disables the entire uart irq; also disable single sources
+  // within it
+  *(uint32_t volatile*) PL011_UART_IMSC = 0;
 }
 
 inline static _Bool can_transmit(void)
diff --git a/uart.h b/uart.h
index ce27d4e..eba292a 100644
--- a/uart.h
+++ b/uart.h
@@ -61,7 +61,7 @@ static inline void uart_irq_enable(void)
 
 static inline _Bool uart_recv_irq_pending(void)
 {
-  return ((uint32_t) 1 << 4) & *(uint32_t volatile*) PL011_UART_RIS;
+  return ((uint32_t) 1 << 4) & *(uint32_t volatile*) PL011_UART_MIS;
 }
 
 static inline void uart_recv_irq_disable(void)
@@ -81,7 +81,7 @@ static inline void uart_clear_recv_irq(void)
 
 static inline _Bool uart_send_irq_pending(void)
 {
-  return ((uint32_t) 1 << 5) & *(uint32_t volatile*) PL011_UART_RIS;
+  return ((uint32_t) 1 << 5) & *(uint32_t volatile*) PL011_UART_MIS;
 }
 
 static inline void uart_send_irq_disable(void)