Move load/save to blkdev_cmds and add a new "poke" builtin shell cmd
that is the mirror of "peek" and strictly uses stdio (no blkdev
involved).
This allows us to slim the minimal OS size but, more importantly, change
the behavior of "load" so that we don't expect GetC to block until Z is
set. This way, using "load X" with X being larger than the blkdev size
won't block forever.
This also brings our RC2014 minimal kernel below the 1K mark again.
The pgm module implements a shell hook so that when an unknown command
is typed, we look into the mounted filesystem and look for a file with
the same name as the command. If we find one, we load it in memory and
run it.
This allows us to break through the 64K limit for includes CFS in zasm,
a limit we were dangerously close to breaking. In fact, this commit
makes us go over that limit. Right in time!
To run a parseExpr on first pass would always return a false success
with dummy value because symbols are configured to always succeed on
first pass. This would make expressions like ".fill 0x38-$" so bad
things to labels because "0x38-$" wouldn't return the same thing on
first and second pass.
Revert to parsing literals and symbols after having scanned for
expressions and add a special case specifically for char literals (which
is why we scanned for literals and symbols first in the first place).
It was a bad idea to remove it. Now that I'm introducing the concept of
a per-app glue file, it becomes much easier to build emulated zasm as a
userspace app.
This shrinks the CFS size to 21k from nearly 64K. This will allow me to
kick the can down the road a bit with regards to supporting storage
seek/tell greater than 64K.
I'll get to it, but first, I want to assemble zasm with zasm!
On build, pack `parts/z80` into a CFS and embed it into the emulated
zasm executable as an fsdev. This will allow for the upcoming include
directive to have something to go to.
For now, this is useless except for inflating the emulated zasm's size.
With the help of the newly-introduced cfspack tool, we can mount a
filesystem in our emulated shell and play around. Read-only for now.
Unpacking incoming.
This will soon allow use to seek and tell on input, which is necessary
for a second pass which is necessary for forward symbol references.
This require making `blkSel` a bit more flexible. Rather than having one
global selected blkdev, each app can select its own, in its own memory
space.
