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Exception Handling on ARM

kamel B

Hi,

Im working on a data-abort handler for the LPC2194 and I've found the Roger Lynx article's here:
www.eetimes.com/.../How-to-use-ARM-s-data-abort-exception

I've found the article good and I want to adapt the example he give in a C code (with inlines directives).
The problem is that I don't understand how to get all registers of the processor in a C table?

Here is the code I've already wrote (working with the line commented in the Handler):

#include <LPC21xx.h>
#include <stdio.h>
#include <stdlib.h>


#define varerror   (*((volatile unsigned long *) 0xEF05006C))
// Définition d'une fonction en dehors de la zone programme
#define Fonction_err() asm volatile ( " B 0x00050000")

#define ENTRER_ISR_Dabt()       asm volatile (" sub   lr, lr,#4\n" \ 
                                                                                  " STMFD sp!,{r0-r12,lr}")

#define SORTIR_ISR_Dabt()       asm volatile (" LDMFD sp!, {r0-r12,pc}^")



void C_Abort_handler() __attribute__((interrupt("Abort")));

// Initialisation de l'UART0 sans interruptions void initUART0(void)

void initUART0(void)
{

        PINSEL0 = 0x0005;       // P0.0 -> transmission/Reception UART0
        U0LCR = 0x83;           // Config + DLAB 1
        U0DLM = 0x00;           // Baud Rate
        U0DLL = 16;             // PLL x1 - 9600 bauds - 10Mhz
        U0LCR = 0x03;           // DLAB 0

}

void send_RS(unsigned char caractere)
{

        while ((U0LSR & 0x20) == 0x00) ;    // Tant que le buffer d'émission contient des données

        U0THR = caractere;
}

// Fonction d'envoi chaine de caractere sur UART0

void send_uart(unsigned char *tabcarac)
{

        int i = -1;

        do {
                i++;
                send_RS(*(tabcarac + i));

        } while (*(tabcarac + i) != 0x00);

}

int main(void)
{

        //Init P1.16
        IODIR1=0X00010000;      //p1.16  en sortie

        initUART0();

        send_uart("                C_DATA_ABORT HANDLER\r\n\0");
        send_uart("                  BOUHARA Kamel\r\n\0");
        // Ecriture interdite
        varerror = 0x1;

        // Erreur de fonction
        Fonction_err();
        while(1);
}

void C_Abort_handler()
{

        long dabort_dump[256];          //tableau des 15 regs + cpsr (= 72 octets)
        volatile unsigned long *lnk_ptr;
        volatile unsigned long cpsr, spsr;
        char adr[20], cur_mode[20], exc_mode[20],stack[75];

        ENTRER_ISR_Dabt();

//      asm volatile ("stmfd sp!, {r0-r12,lr}");
//      asm volatile ("ldr sp, =(dabort_dump+5*4)");
//      asm volatile ("stmia sp, {r0-r15}");  //sauv. des regs
        asm volatile ("sub lr, lr, #8");      //récupère l'adresse de l'instruction d'exception
        asm volatile ("mov %0, lr":"=r" (lnk_ptr)); //adresse récupérer dans variable en C
        asm volatile ("mrs %0, cpsr":"=r" (cpsr));  //cpsr = r5
        asm volatile ("mrs %0, spsr":"=r" (spsr));  //spsr= r6
        //asm volatile ("mov r2, r6");        //r2 = cpsr (de l'exception)

        send_uart("Handling data abort exception...\r\n\0");
        sprintf(adr,"Data abort exception at %p value 0x%lX\r\n", lnk_ptr,*(lnk_ptr));
        send_uart(adr);

        sprintf(cur_mode,"Current CPU MODE (cpsr): 0x%lX\r\n",&cpsr);
        send_uart(cur_mode);

        sprintf(exc_mode,"Exception CPU MODE (spsr): 0x%lX\r\n",&spsr);
        send_uart(exc_mode);

        sprintf(stack,"sp : 0x%lX\r\n",&dabort_dump);
        send_uart(stack);

        for(;;);

}</prev>


Regards.