INSTALL

Make sure you have development packages for SDL and libjansson installed.
Under Debian (and likely Ubuntu) it's as simple as:

 $ sudo apt-get install libsdl1.2-dev libjansson-dev

Then just do:

 $ cd path/to/valkyrie
 $ make

This will generate the bin/valkyrie binary. To run the bootrom with valkyrie,
type:

 $ bin/valkyrie -R $PATH_TO_ROM_DIRECTORY -r hikaru_0.92

If you want to run a game, you have to also enable a hack that fakes the
IO board a little bit better, as follows:

 $ MIE_HACK=1 bin/valkyrie -R $PATH_TO_ROM_DIRECTORY -r airtrix

If you forget to enable the hack, the game will either get stuck, or endlessly
display an "I/O board initializing" screen.

If you are a developer, and want to display on screen the contents of the
frame buffer or texture RAM, to see what gets uploaded, then set the
HR_DRAW_FB or HR_DRAW_TEXRAM environment variables, as follows:

 $ MIE_HACK=1 HR_DRAW_TEXRAM=1 bin/valkyrie -R $PATH_TO_ROM_DIRECTORY -r airtrix

You can also install valkyrie for your user with:

 $ make install

This will compile and install a copy of the valkyrie binary in ~/.local/bin
and a copy of vk-games.json (the game description list used by valkyrie) in
~/.local/share/valkyrie. After this step, you can just do:

 $ valkyrie -R $PATH_TO_ROM_DIRECtory -r $ROM_NAME

from anywhere in your filesystem.
 
XXX: due to the (dumb) way the loading code is designed, the ROM_DIRECTORY
is expected to contain a sub-directory for each game, containing the
uncompressed ROM images _and_ a copy of (or a symlink to) the BOOTROM image.
The latter should be named `hikaru_0.X.bin', where X is the bootrom version,
that is, one of 84, 92 or 96. I *know* it is very rough, patches are welcome.

XXX: while valkyrie can run all three BOOTROM versions, it only supports
loading games using version 0.92; so make sure you are linking version 0.92
in the ROM directories!