Error when compiling with DT_INTS_3_4b"

[tumbleweed]

Well, it turned out that there are so many changes required to get umcbuild to use mpasmx it just wasn't worth the bother.

Here's the asm source for a UMC loader that works with the K40 (at least the 27K40... the only one I tried).
You'll have to change the entries in the USER CONFIGURATION SECTION to match what you're using.
Right now it's setup for an 18F27K40, 16MHz intosc, and uart1 on RC6/RC7.

There are no other files required except for the mpasmx p18FxxK40.inc file. Don't use umcbuild.exe... just assemble it with mpasmx

[Dave]

Thanks Tumbleweed, I will give it a try when I get home from work tonight and let you know.

[Dave]

Well Tumbleweed, I just couldn't wait to try it out. It all looks good. The only error I got when compiling was "undefined symbol":

; check to make sure program fits 26-5-2018
#if $ > DEVICE_ROM
error "program code exceeds flash size. change LOADER_SIZE_MIN"
#endif

I just commented them out and away we go....

Once again, Thanks for the mod's.

[tumbleweed]

The only error I got when compiling was "undefined symbol":

That's odd... I don't get that.

That size check is there to make sure the loader doesn't grow bigger than what's reserved (this one's a bit larger at 512 bytes vs 384).
What version of mpasmx are you using? I was using 5.77

[Dave]

It says, V5.778 in the toolchain. I did notice and have worked on trying to get the bootloader to work with usart2 with no success. I don't understand why?
I have attached the modified version. Maybe if you can, take a look?

[tumbleweed]

All of the control registers for UART1 are in the access bank so you can get away with not using banksel to get to them.
UART2 registers are in a different bank (bank 14, 0x0E99-0x0E9F) so you have to load the BSR (ie BANKSEL RC2STA) to access them.

You can still use UART1 but assign it to different pins with the PPS... that would be a lot easier (and smaller) than adding all the code to get at UART2.

[Dave]

Tumbleweed, I think I will go the ( BANKSEL RC2STA) route because I use the uart1 for different communications to remote arrays. Thanks for the advice, I should have seen that. I am by no means an asm guru but I do know enough to get into trouble.....

[Dave]

Well, This has been a prosperous morning as I have the bootloader running on com2. For this project I need to bootload it over Bluetooth. Thanks so much Tumbleweed for the advice. I can see a whole new future with these K40's.... Thanks...