Minor bug with bootloader, please read

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Minor bug with bootloader, please read

Postby vbriel » Oct Thu 21, 2010 1:19 pm

Ok, so this little bug just cost me 2 days of work. I did a small mod on the firmware and decided to program it the way users will by putting the code onto SD card and doing a system flash update. Everything appears to work great but then I noticed that the firmware version didn't change. OH NO, flash updates are not working. After a lot of work, headaches, throwing chips across the room in a fit, I found the problem. The bootloader section of the CPU is a special section of memory that contains code specific for updating the CPU chips software section of flash. It is protected. If you look at the firmware listing, you will find a line of code that looks like this:

Code: Select all
   .EQU   FIRMVER   =   3


This piece tells us which version of firmware we have. The idea was, I could just change the FIRMVER value to the new value and like magic, the system would display the new version after programming. The error in this is that this piece of code, even though it was written inside the program space, is actually stored in the bootloader. This means that when an update is done, this value does NOT get changed, can not get changed.

So, for now, until I come up with a good fix, the firmware version will not change when an update is released. After I get caught up on orders, I'll fix this.

Vince
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Re: Minor bug with bootloader, please read

Postby hal2710 » Feb Mon 07, 2011 12:28 pm

Hi Vince,

Just wondering how you're getting on with the new firmware update ?


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Re: Minor bug with bootloader, please read

Postby vbriel » Feb Wed 09, 2011 1:17 pm

We have a much improved firmware version thanks to Al and Garry. We are running tests on it now but it appears pretty stable. It would be best if you have a 20mhz crystal in your Altair micro to drop down to 16mhz for stability reasons. This update should be a manual one where I send you a chip out. However, there is another Atmel shortage on the ATmega8515 until May or June. So, what I'll probably do is ask you to send in your chip for reprogramming. After this update, the bootloader is very stable and won't require you to send in your chip. If you can't send in your chip, I have some available but I planned on using these for the future RAM drive disk drive emulation board I'm designing.

If you want to send you chip in email me at vbriel@yahoo.com or vince@brielcomputers.com and I'll work it out with you. The official release is coming soon. The upgrade will allow email and posted updates to be done so you won't have to send in a chip for programming. The bootloader had a bug that some chips wouldn't update. That's fixed with this version and is a smart bootloader too. More info will be available soon.

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