collapseos/recipes/rc2014/selfhost

Assembling Collapse OS from within it

This is where we tie lose ends, complete the circle, loop the loop: we assemble a new Collapse OS entirely from within Collapse OS and write it to EEPROM, either for another RC2014 or for an OS upgrade.

Gathering parts

• stage4 from sdcard recipe. If you want to write to EEPROM as the final step, you'll need a hybrid stage4 that also includes stuff from the eeprom recipe.

Building stage 1

Part 1

Building the first part of stage 1 (the binary part, before the inlined-source part) from within Collapse OS is actually very similar from building it from a modern environment. If you take the time to look at the base recipe Makefile, you'll see cat xcomp.fs | $(STAGE2). That command builds part 1. Open xcomp.fs in a text editor and take a look at it.

To assemble stage 1 from RC2014, all you need to do is to type those commands in the same order, and replace the H@ 256 /MOD 2 PC! 2 PC! lines with H@ .X. Those commands will inform you of the begin/end offsets of the assembled binary.

The meaning of these commands is not explained here. You are encouraged to read the in-system documentation for more information.

However, one thing you should know is that because the SD card driver is a bit slow, some of these commands take a long time. Multiple minutes. Be patient.

Once all your commands are run and that you have your begin/end offset (write them down somewhere), you're ready to assemble part 2.

What to do on SDerr?

If you get SDerr in the middle of a LOAD operation, something went wrong with the SD card. The bad news is that it left your xcomp operation in an inconsistent state. If your at the beginning of it, it's easier to restart it entirely.

If you're towards the end, you might want to repair it. To do so, you'll have to bring your XCURRENT and HERE values to where they were before the LOAD operation. You could have thought ahead and printed them before the LOAD, but if you didn't, you'll just have to dig in your memory with DUMP.

You're looking at the offset of the last wordref of the previous LOAD operation. That offset is going in XCURRENT. Then, you're looking at the end of that word. That offset goes in HERE. Once you've done that, relaunch your LOAD.

Part 2

TODO