I’ve tried to initialize a UART RX interrupt (when RX buffer has a character, trigger the interrupt)
It didn’t work.
I’ve tried IAR example “/simple/uart” and I injected my code there. In their project with my code, interrupt worked. In my project with the same C code, didn’t.
The only difference was the presence of cstartup.s
Can I avoid this file?
What can I do in my source code to avoid including this file? (i hate using someone else code)
Part of cstartup file:
__iar_program_start:
?cstartup:
I_Bit DEFINE 0x80 ; when I bit is set, IRQ is disabled
F_Bit DEFINE 0x40 ; when F bit is set, FIQ is disabled
#define VIC_INT_ENABLE 0xFFFFF014
; Disable all interrupts
ldr r0,=VIC_INT_ENABLE
mov r1,#0xFFFFFFFF
str r1,[r0]
; Execution starts here.
; After a reset, the mode is ARM, Supervisor, interrupts disabled.
; Initialize the stack pointers.
; The pattern below can be used for any of the exception stacks:
; FIQ, IRQ, SVC, ABT, UND, SYS.
; The USR mode uses the same stack as SYS.
; The stack segments must be defined in the linker command file,
; and be declared above.
mrs r0,cpsr ; Original PSR value
bic r0,r0,#MODE_MSK ; Clear the mode bits
orr r0,r0,#SVC_MODE ; Set Supervisor mode bits
msr cpsr_c,r0 ; Change the mode
ldr sp,=SFE(SVC_STACK) ; End of SVC_STACK
bic r0,r0,#MODE_MSK ; Clear the mode bits
orr r0,r0,#UND_MODE ; Set Undefined mode bits
msr cpsr_c,r0 ; Change the mode
ldr sp,=SFE(UND_STACK) ; End of UND_MODE
bic r0,r0,#MODE_MSK ; Clear the mode bits
orr r0,r0,#ABT_MODE ; Set Data abort mode bits
msr cpsr_c,r0 ; Change the mode
ldr sp,=SFE(ABT_STACK) ; End of ABT_STACK
bic r0,r0,#MODE_MSK ; Clear the mode bits
orr r0,r0,#FIQ_MODE ; Set FIR mode bits
msr cpsr_c,r0 ; Change the mode
ldr sp,=SFE(FIQ_STACK) ; End of FIQ_STACK
bic r0,r0,#MODE_MSK ; Clear the mode bits
orr r0,r0,#IRQ_MODE ; Set IRQ mode bits
msr cpsr_c,r0 ; Change the mode
ldr sp,=SFE(IRQ_STACK) ; End of IRQ_STACK
bic r0,r0,#MODE_MSK | I_Bit | F_Bit ; Clear the mode bits
orr r0,r0,#SYS_MODE ; Set System mode bits
msr cpsr_c,r0 ; Change the mode
ldr sp,=SFE(CSTACK) ; End of CSTACK
part of my C code
extern void init_irq()
{
DWORD volatile *pVectorAddress;
DWORD volatile *pVectorPriority;
/* all irq channels assigned to IRQ */
VICINTSELECT = 0;
/* disable all interrupts*/
VICINTENCLEAR = 0xFFFFFFFF;
/* clear all software interrupts */
VICSOFTINTCLEAR = 0xFFFFFFFF;
/* VIC registers can be accessed in User or privileged mode */
VICPROTECTION_bit.VIC_ACCESS = 0;
/* Clear interrupt */
VICADDRESS = 0;
/* Clear all adresses for vectors */
pVectorAddress = &VICVECTADDR0;
pVectorPriority = &VICVECTPRIORITY0;
for(DWORD i = 0; i < VIC_SIZE; i++)
{
*pVectorAddress++ = 0x00;
*pVectorPriority++ = 0x0F;
}
}
extern BOOL add_irq_handler( DWORD dwIntNumber, void *IntFunction, DWORD dwPriority )
{
DWORD *pVectorAddress;
DWORD *pVectorPriority;
VICINTENCLEAR = 1 << dwIntNumber; // disable Interrupt
if ( dwIntNumber >= VIC_SIZE ) // maximum nr. of interrupt sources is 32
return ( FALSE );
pVectorAddress = (DWORD )( 0xFFFFF100 + dwIntNumber4);
pVectorPriority = (DWORD )(0xFFFFF200 + dwIntNumber4);
*pVectorAddress = (DWORD)IntFunction; // set interrupt vector
*pVectorPriority = dwPriority;
//VICINTSELECT = 1 << dwIntNumber;
VICINTENABLE = 1 << dwIntNumber; // enable interrupt
return TRUE;
}