History

Virgil Dupras ae028e3a86 blockdev: make implementors "random access" 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.	2019-06-04 15:36:20 -04:00
..
zasm	blockdev: make implementors "random access"	2019-06-04 15:36:20 -04:00
README.md	Make userspace parse args the same way the shell does	2019-06-02 14:05:20 -04:00

Virgil Dupras ae028e3a86 blockdev: make implementors "random access"

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.

2019-06-04 15:36:20 -04:00

zasm

blockdev: make implementors "random access"

2019-06-04 15:36:20 -04:00

README.md

Make userspace parse args the same way the shell does

2019-06-02 14:05:20 -04:00

README.md

User applications

This folder contains code designed to be "userspace" application. Unlike the kernel, which always stay in memory. Those apps here will more likely be loaded in RAM from storage, ran, then discarded so that another userspace program can be run.

That doesn't mean that you can't include that code in your kernel though, but you will typically not want to do that.

Userspace convention

We execute a userspace application by calling the address it's loaded into. This means: a userspace application is expected to return.

Whatever calls the userspace app (usually, it will be the shell), should set HL to a pointer to unparsed arguments in string form, null terminated.

The userspace application is expected to set A on return. 0 means success, non-zero means error.