99 lines
3.7 KiB
Plaintext
99 lines
3.7 KiB
Plaintext
# 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.
|
|
|
|
Build Collapse OS' from within Collapse OS is very similar to
|
|
how we do it from the makefiles in /arch. If you take
|
|
the time to look one, you'll see something that look like "cat
|
|
xcomp.fs | $(STAGE)". That's the thing. Open "xcomp.fs" in a
|
|
text editor and take a look at it. Some xcomp units are simple
|
|
proxy to a block, which you'll find in the blk/ subfolder for
|
|
this recipe.
|
|
|
|
To assemble Collapse OS from within it, all you need to do is
|
|
execute the content of this unit, minus the 2 lines of "spitting
|
|
to port 2" at the end of the unit, which is a special signal for
|
|
the stage binary.
|
|
|
|
The rest can be executed on any Collapse OS system with enough
|
|
memory. It will yield a binary in memory. To know the start/end
|
|
offset of the binary, you'll type the same two commands at the
|
|
end of xcomp.fs, but replace the "/MOD 2 PC! 2 PC!" words with
|
|
".X". Then, write that binary between those offsets on your
|
|
target media. That binary should be the exact same as what you
|
|
get in "os.bin" when you run "make". You now have a new Collapse
|
|
OS deployment.
|
|
|
|
Is that it? Yes. But for your own enlightenment, let's look at
|
|
the xcomp unit in more details. Full details are at
|
|
doc/bootstrap.txt.
|
|
|
|
The first part is configuration of your new system. When RAM
|
|
starts, where RSP and PSP start, what ports to use for what
|
|
device, etc. These configuration declarations are expected in
|
|
the boot code and driver code.
|
|
|
|
Then, we load the proper assembler and the cross compiler (xcomp
|
|
for short), which we'll of course need for the task ahead.
|
|
|
|
Then come xcomp overrides, which are needed for xcomp to be
|
|
effective.
|
|
|
|
At this point, we're about to begin spitting binary content,
|
|
this will be our starting offset. "ORG" will soon be set to your
|
|
current "H@".
|
|
|
|
Then, we assemble the boot binary, drivers' native words, then
|
|
inner core, close the binary with a hook word. We're finished
|
|
with cross-compiling.
|
|
|
|
We're at the offset that will be "CURRENT" on boot, so we update
|
|
"LATEST".
|
|
|
|
Then, we spit the init source code that will be interpreted on
|
|
boot. And... that's it!
|
|
|
|
# What to do on SDerr?
|
|
|
|
If you self host from a machine with a SD card and 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. The easiest thing to do it
|
|
to restart the operation from scratch. Those error are not
|
|
frequent unless hardware is faulty.
|
|
|
|
# Cross-compiling directly to EEPROM
|
|
|
|
If your target media is a RAM mappable media, you can save prec-
|
|
ious RAM by cross-compiling Collapse OS directly to it. It req-
|
|
uires special handling.
|
|
|
|
You can begin the process in a regular manner, but right before
|
|
you're about to assemble the boot code, take a pause.
|
|
|
|
Up until now, you've been loading your cross compiling tools in
|
|
RAM, now, you're about to write Collapse OS. So what you need
|
|
to do is change HERE to the address of your EEPROM. Example:
|
|
|
|
0x2000 HERE !
|
|
|
|
If you need to activate special system overrides such as the
|
|
one described in doc/hw/at28.txt, now is the time.
|
|
|
|
Then, you can continue the process normally.
|
|
|
|
# Verifying
|
|
|
|
You can use "/tools/memdump" to dump the memory between your
|
|
begin/end offsets so that you can compare against your reference
|
|
stage 1. Before you do, you have to take yourself out of xcomp
|
|
mode. First, run XCOFF to go back to your regular dict. Then,
|
|
run "FORGET CODE" to undo the xcomp overrides you've added
|
|
before. That will rewind HERE. You don't want that. Put HERE
|
|
back to after your ending offset so that you don't overwrite
|
|
your binary.
|
|
|
|
Then, you can run "/tools/memdump".
|