A while ago I posted a thread entitled "What the hell is a bootloader". Since then I have learnt the basics of what a bootloader actually is. I have a couple more questions:
1) How does a bootloader write to the internal flash? I though only an external programmer could do that?
2) How would I go about writing my own bootloader, so that I can reprogram the device into external (I2C eeprom) to prevent the wearing of the chip's flash, and have a progress bar on an LCD screen?
3) What is the smallest bootloader avaliable (for a AT90S8535 micro)?
4) Would running the program out of an I2C eeprom significantly slow the program down?
Thanks for all/any replies. I am working on a device that uses a commercial minature board with a SM 8535 on it, plus serial chip, power supply, etc. and so cannot use a larger micro, but I want to use programs larger than the internal 8k - hence the want for an external I2C eeprom. Luckily, I happen to have 2 I/O's left. When the device goes commercial, I also want a serial (using the bootloader) programming port to update the firmware of the device while the LCD shows the progress/debug info.
- Dean :twisted: