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Hello,
I am tasked with porting my LPC2478 bootloader to a LPC1768. I have read the documentation and I'm fully aware of the differences in boot behavior but I just can't get it right - here is the problem: Once my bootloader jumps to applicaton, the processor treats (as far as I could tell) the beginning of the vector table as code - not fetching the initial SP and the reset vector (=execution start address) followed by a jump to that address. It goes on, until an STM instruction is executed to internal flash - after which it is all over. This is only my second day really working with an LPC1768 - can you clarify what I'm doing wrong?
John,
One major difference between an ARM7 device and a Cortex-M3 is the content of the vector table: when you jump to application in an ARM7, you can expect code inside the vector table, so you can jump to its beginning and know you are correct. The vector table of a Cortex-M3 needs to be dereferenced in order to retrieve the entry point to the application.
The Cortex-M3 is designed to allow 100% C code - you can implement all of the startup code in C.
And there are no special ISR prologes/epiloges which means that there is no need for any interrupt keyword for an ISR either.