e06ca69b2f
via xmodem to the DBGU port when the AT91 comes up in recovery mode. The recovery loader will then load your program via xmodem into SDRAM at 1MB which can do its things. It needs to be tweaked to the specific board one is using, but it fits in < 1kB (all of Atmel's ARM products have at least 8kb of SRAM that I can tell, so this should work for them all). Parts of this code were provided by Kwikbyte with copyright specifically disclaimed. I heavily modified it to act as a recovery loader (before it was a bootstrap loader) and to optimize for size (before I started the size was closer to 8k). Bootstrap loaders for SPI and IIC to follow.
8 lines
357 B
Plaintext
8 lines
357 B
Plaintext
This is a bootstrap bootloader. It is intended to be used when the
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AT91RM9200 is running xmodem over DBGU. It will download the next stage
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of the booting process (or the recovery program) and jump to it. It loads
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the program at a 1MB offset into SDRAM. Programs are expected to be
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smaller than this and copy themselves to the right location.
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$FreeBSD$
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