This is all the bits you need to play with recent linux on mc68000
- Press the bootloader button and then reset button
- Open minicom, set your baud to 9600
- Open the transfer methods configuration and update ascii to
ascii-xfr -dsv -l 1
. This adds a delay between lines for the mc68ez328 bootloader to catch up. - Open the file transfer menu and send the u-boot SPL
payload.b
via ascii - Send
0040000000
to jump to the SPL - Wait for the SPL to boot and start printing CCC..
- Open the file transfer menu and send the u-boot binary
u-boot.img
- Wait for u-boot to boot. The SPL will complain the CRC is incorrect. This is due to some things being mapped over the memory in bootloader mode.
- Send the command
mw.l 0x100000 0xffffffff 0x12000; loady 0x100000 57600
to clear the target memory and start loading over ymodem. Follow the u-boot prompt to change the baud rate. - Send
u-boot.bin
(Needs to be the .bin not .img as we need it without the header) - Erase the first part of the flash and write u-boot there with
erase 0x10000000 0x48000; cp.l 0x100000 0x10000000 0x12000
- You should now be able to reset and see u-boot load up from flash.
- On an SD card you need:
- 2 or more partitions.
- The first should be FAT formatted.
- The second shouldn't be formatted.
- Put the kernel elf on the FAT partition
- dd the squashfs rootfs to the second partition.
J4:
- 13 (SCLK) -> SD clk
- 15 (STXD) -> SD MOSI
- 16 (SRXD) -> SD MISO
- 2 (PD0) -> SD CS
- 1 (PD1) -> SD vcc on (Optional but might be needed to get some cards to init)