further ivt and isr implementation

general (dummy) exception or interrupt handlers show exception number
(from VTOR status register)

diff --git a/include/mmap.h b/include/mmap.h
index d0f9338..6f4fabb 100644 (file)
--- a/include/mmap.h
+++ b/include/mmap.h
@@ -15,6 +15,7 @@
 
 /* SYSTEM CONTROL BLOCK REGISTER */
 #define SCB_VTOR ((volatile uint32_t *)( 0xE000ED08)) // VECTOR TABLE
+#define SCB_VTOR_ST ((volatile uint32_t *)( 0xE000ED04)) // STATUS OF VECTOR
 
 /* NESTED VECTOR INTERRUPT CONTROL REGISTER */
 #define NVIC_ISER0 ((volatile uint32_t*)( 0xE000E100)) // interrupt set enable register

diff --git a/ivt.c b/ivt.c
index 6df1e8b..183713f 100644 (file)
--- a/ivt.c
+++ b/ivt.c
@@ -32,36 +32,47 @@ struct interrupt_frame {
  * service routine:  
  *
  * interrupt vector 1-15: processor exceptions
- * interrupt vector 16-64: irq0 - irq ..
+ * interrupt vector 16-92: irq0 - irq ..
  * */
 
-uint32_t ivt[64];
+uint32_t ivt[92];
 
 /* each message corresponds to each and every exception. 
  * We get the correct message by accessing
  *  exception_message[interrupt_number] 
  *  exception_message[0] is not used (=MSP)*/
-unsigned char *exception_messages[] =
-{
-    "--",
-    "RESET",
-    "NMI",
-    "HARD FAULT",
-    "MEMMANAGE FAULT",
-    "BUS FAULT",
-    "USAGE FAULT",
-    "RESERVED",
-    "SVC",
-    "DEBUG MONITOR",
-    "RESERVED",
-    "PENDSV",
-    "SYSTICK",
-    "IRQ1",
-    "IRQ2",
-    "IRQ3",
-    "IRQ4",
-    // add more if needed
-};
+
+char * exception_message(uint8_t intnr) {
+
+       char * messages[] = {
+           "--",
+           "RESET",
+           "NMI",
+           "HARD FAULT",
+           "MEMMANAGE FAULT",
+           "BUS FAULT",
+           "USAGE FAULT",
+           "RESERVED",
+           "SVC",
+           "DEBUG MONITOR",
+           "RESERVED",
+           "RESERVED",
+           "RESERVED",
+           "RESERVED",
+           "PENDSV",
+           "SYSTICK",
+           "IRQ1",
+           "IRQ2",
+           "IRQ3",
+           "IRQ4",
+           // add more if needed
+       };
+
+       if (intnr < 20) // TODO: strlen
+               return messages[intnr];
+
+       return NULL;
+}
 
 void ivt_set_gate(unsigned char num, void * isr(), short pri) {
 
@@ -75,21 +86,11 @@ void ivt_set_gate(unsigned char num, void * isr(), short pri) {
 __attribute__ ((interrupt)) 
 void * dummy_isr(struct interrupt_frame * frame) {
 
-
-       uint32_t * p = (volatile uint32_t *) 0x21000000;
-
-       addrtohex(frame->r0);
-       addrtohex(frame->r1);
-       addrtohex(frame->r2);
-       addrtohex(frame->r3);
-       addrtohex(frame->r12);
-       addrtohex(frame->lr);
-       addrtohex(frame->pc);
-       addrtohex(frame->psr);
+       uint8_t nr = *SCB_VTOR_ST & 0xFF;
        
-       //__asm__ __volatile__ ("MRS r0, IPSR");
-       //addrtohex(frame->r0);
-       uart_puts("EXCEPTION X: SYSTEM HALTED\n");
+       uart_puts("EXCEPTION: ");
+       uart_puts(exception_message(nr));
+       uart_puts("\nSYSTEM HALTED\n");
        
        for(;;);
 }
@@ -98,13 +99,13 @@ void * dummy_isr(struct interrupt_frame * frame) {
 void ivt_init() {
 
        /* clear entiry IVT, in SRAM location for SRAM + .data (in .bss section) */
-       memset(&ivt, 0, (sizeof(uint32_t) * 87));
+       memset(&ivt, 0, (sizeof(uint32_t) * 92));
 
        // stack top is loaded from the first entry table on boot/reset
        // don't need to relocate or init this here
        extern void * reset,  * nmi, * hardfault;
 
-       for (int i = 1; i < 7; i++) {
+       for (int i = 1; i <= 6 ; i++) {
                ivt_set_gate(i, dummy_isr, 0);
        }
 

diff --git a/link.ld b/link.ld
index 8301b2c..085ab79 100644 (file)
--- a/link.ld
+++ b/link.ld
@@ -14,9 +14,9 @@ SECTIONS
        {
                /* (.vector_table */ 
                *(.text)
-
-       } 
-       . = 0x20000000;
+               *(.rodata)
+       }
+        . = 0x20000000;        
        .data :  
        {
                *(.data)
@@ -24,5 +24,6 @@ SECTIONS
        .bss : ALIGN(256)
        {
                *(.bss)
-       } 
+       }
+               _endofbss = .;  
 }

diff --git a/main.c b/main.c
index 4134c95..c8a47aa 100644 (file)
--- a/main.c
+++ b/main.c
@@ -46,8 +46,8 @@ void main()
        ivt_init();
 //     clock_init();
        uart_init();
-//     systick_init();
        uart_puts("LOADING SYSTEM 0.1 ...\n");
+       systick_init();
        sysinfo();
        mm_init();
 
@@ -61,11 +61,6 @@ void main()
        //regw_u32(p, 0x0CCCCCCCC, 4, 0x01);
 
        //regw_u8(p, 0xFF, 0, 0x02);
-       
-       //addrtohex(*p);
-
-       //addrtohex((volatile uint32_t) 0x12345678 );
-       //addrtohex((volatile uint32_t) SCB_VTOR );
 
 //     asm("cpsie i"); // enable irq , cpsied f (disable faukts(
 

diff --git a/start.asm b/start.asm
index d8c7244..e4ca237 100644 (file)
--- a/start.asm
+++ b/start.asm
@@ -34,7 +34,7 @@ stub:
        mov R1,#0
        udiv.w R2, R0, R1 */
 
-/*     .data
-       .word 'x' */
+       .data
+       .word 'x' 
        .end
 

diff --git a/systick.c b/systick.c
index 48065ef..e90714a 100644 (file)
--- a/systick.c
+++ b/systick.c
@@ -16,19 +16,11 @@ struct interrupt_frame {
         uint32_t psr; // N-4
 };
 
-
-/* void * systick_handler() {
-
-//     *RANDOM_ADDR = (volatile uint32_t) 0x10101010 ;
-//     uart_puts("TEST");
-} */
-
 __attribute__ ((interrupt))
 void * systick_handler(struct interrupt_frame * frame) {
 
+       uint32_t volatile status;
        uart_puts("TICKING\n");
-//     addrtohex((uint32_t) 0x12345678);
-       //      for(;;);
 }
 
 
@@ -41,7 +33,7 @@ void systick_init() {
        /* The counter reload register here holds 
         * 0x1000 -- that's 4096 clock cycles -- if 
         * it is down to zero it is restores the value */
-       *STK_RELOAD = (volatile uint32_t) 0x00000400; 
+       *STK_RELOAD = (volatile uint32_t) 0x00400000; 
 
        /* Every time the counter counts down to zero
         * a systick exception is asserted. Systick has

diff --git a/uart.c b/uart.c
index 4751645..86bf9fe 100644 (file)
--- a/uart.c
+++ b/uart.c
@@ -12,13 +12,14 @@
 
 void * uart_handler() {
 
-       uart_puts("\n echo: ");
+       uart_puts("echo: ");
        while (RXNE) {
                char echochar = *USART1_DR;
-       //      regw_u8(USART1_DR, echochar, 0, O_WRITE);
-       uart_putc(echochar);
-       }  
-//for(;;);
+               //regw_u32(USART1_DR, echochar, 0, O_WRITE);
+               uart_putc(echochar);
+       }
+       uart_putc('\n');
+               
 
 }
 void uart_init() {