ae028e3a86
This huge refactoring remove the Seek and Tell routine from blockdev implementation requirements and change GetC and PutC's API so that they take an address to read and write (through HL/DE) at each call. The "PTR" approach in blockdev implementation was very redundant from device to device and it made more sense to generalize. It's possible that future device aren't "random access", but we'll be able to add more device types later. Another important change in this commit is that the "blockdev handle" is now opaque. Previously, consumers of the API would happily call routines directly from one of the 4 offsets. We can't do that any more. This makes the API more solid for future improvements. This change forced me to change a lot of things in fs, but overall, things are now simpler. No more `FS_PTR`: the "device handle" now holds the active pointer. Lots, lots of changes, but it also feels a lot cleaner and solid. |
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|---|---|---|
| .. | ||
| cfsin | ||
| .gitignore | ||
| glue.asm | ||
| Makefile | ||
| README.md | ||
| user.h | ||
Assembling binaries
For a system to be able to self-reproduce, it needs to assemble source z80 assembly to binary.
Goals
Have a RC2014 assemble a Collapse OS kernel with its source living on a CFS on a SD card.
Work in progress: for now, we compile a simple hello.asm source file.
Gathering parts
- Same parts as the SD card recipe.
The zasm binary
To achieve our goal in this recipe, we'll need a zasm binary on the SD card.
This zasm binary needs to be compiled with the right jump offsets for the kernel
we build in this recipe. These offsets are in user.h and are closely in sync
with the configuration in glue.asm.
user.h is then included in apps/zasm/glue.asm.
The makefile in this recipe takes care of compiling zasm with the proper
user.h file and place it in cfsin/zasm
The userland source
The code we're going to compile is cfsin/hello.asm. As you can see, we also
include user.h in this source code or else ld hl, sAwesome would load the
wrong offset.
Because of this, the Makefile takes care of copying user.h in our filesystem.
Preparing the card and kernel
After running make, you'll end up with sdcard.cfs which you can load the
same way you did in the SD card recipe.
You will also have os.bin, which you can flash on your EEPROM the same way
you already did before.
Running it
Compiling and running hello.asm is done very much like in
the shell emulator:
Collapse OS
> sdci
> fson
> fopn 0 hello.asm
> zasm 2 1
> mptr 8600
> bsel 1
> seek 00 0000
> load ff
> call 00 0000
Assembled from a RC2014
That RC2014 is starting to feel powerful now, right?