So, I managed to fish out this line from APP_isrUart(void) in the file uart.c from JN-AN-1217.
unsigned int irq = ((*((volatile uint32 *)(UART_START_ADR + 0x08))) >> 1) & 0x0007;
To setup UART1, it is just UART_START_ADR -> UART1_START_ADR as written in the same uart.c file.
Now, how do I do the same for SPI ?
What should the settings be ?
What does (UART_START_ADR + 0x08))) >> 1) & 0x0007; do ? How should it be for SPI or any other peripheral that has interrupts ?