I'm using interrupt_handler.c for a bootloader without a softdevice from this source. Interrupt handling in the main app seems to work fine. But interrupts in the bootloader leading to a reset.
For example my uart interrupt.
- on an uart interrupt section bootloop is called
- jumps to uart0
- jumps to execute
- execute jumps to 0x0000 0000
Why?
[uart.c]
void UART0_IRQHandler_Bootloader(void)
{
// some code
}
[interrupt_handler.c]
bootload
CMP R0, #0x24;
BEQ swi0
CMP R0, #0x21;
BEQ rtc1
CMP R0, #0x16;
BEQ gpiote
CMP R0, #0x12;
BEQ uart0
//RETURN code needed
uart0
EXTERN UART0_IRQHandler_Bootloader[WEAK]
LDR R0,=UART0_IRQHandler_Bootloader
B execute ;
execute
BX R0 ;
I did some investigations: R0 is loaded with 0x0000 0000 is above example. When removing [WEAK] everything works as expected. Leaving [WEAK] linker (Keil 5.14) is removing UART0_IRQHandler_Bootloader section.
Removing Unused input sections from the image.
Removing main.o(.rev16_text), (4 bytes).
Removing main.o(.revsh_text), (4 bytes).
Removing main.o(i.init), (60 bytes).
Removing uartreader.o(.rev16_text), (4 bytes).
Removing uartreader.o(.revsh_text), (4 bytes).
Removing uartreader.o(i.UART0_IRQHandler_Bootloader), (140 bytes).
Removing uartreader.o(.bss), (50 bytes).
Removing arm_startup_nrf51.o(HEAP), (1024 bytes).
Removing system_nrf51.o(.rev16_text), (4 bytes).
Removing system_nrf51.o(.revsh_text), (4 bytes).
Removing system_nrf51.o(i.SystemCoreClockUpdate), (16 bytes).
11 unused section(s) (total 1314 bytes) removed from the image.
