topic Re: Bootloader in LPC Microcontrollers

Bootloader

ianbenton — Wed, 16 Sep 2020 18:53:02 GMT

I'm trying to persuade MUCXpresso to generate the code to put in a serial EEPROM which can then be bootloaded to update software.

It's going reasonably well. I found out how to turn the code into a .hex or .s19 file which I can load into my EEPROM programmer, and I found out how to edit the Linker file so that it doesn't generate the data and bss tables.

I'd really like the code to start at the beginning of the file, and there is one half-word that I can't seem to get rid of.

The first hword is always an instruction that branches to itself. Any ideas?

It's an LPC1517, by the way.

Re: Bootloader

FelipeGarcia — Thu, 17 Sep 2020 23:19:54 GMT

Hi,

At reset, vector table is located at 0x0 and you cannot control this. Once the execution starts you can relocate vector table using VTOR.

Best regards,

Felipe

Re: Bootloader

ianbenton — Fri, 18 Sep 2020 19:36:08 GMT

The code to be loaded doesn't have a vector table.

When the assembler produces the output file, it normally starts with a B pc-2 instruction, followed by the .data and .bss tables.

Editing the linker file to remove the .data and .bss tables, but I can't get rid of the B pc-2 instuction.