All of the SD card commands are moved into their own file, with
functions sd_init, sd_get_rca, sd_select_card, sd_get_status, and
sd_readblock.
The FAT functions are movied into fat.c and give functions fat_init and
fat_read. Note that the filename is ignored for now, it always reads the
first file in the root directory.
The loading of o65 files is done in o65.c, and executing is done in
exec.c
This cleans up the main file signifigantly and leaves the project open
to expansion.
This will read the data from the sd card, copy it to the originally
linked address (no relocation), then execute it.
I am lazy and wrote it in C using weird function pointer casting but
this would probably be more efficient if it were to be written in
assembly instead.
The test program simply returns 'A', but that is enough to prove that it
is actually running.
Prints out information about the drive, now inside its own function.
Also changes the read function to take in a 32 bit address instead of a
16 bit one.
Attempts to read the first file on the disk
Polls the sd controller until the read flag is set, at which point it
reads 32 bits of data from the controller.
long response codes (such as CID) are not supported in hw or sw.
These series of commands are enough to read the first 512b block off of
the sd card. The RCA is hard coded to the sd card that I have on hand,
since response codes are not supported
This code creates a shared mapping in high ram, makes sure that that
works, and also makes sure that the memory which is mapped over is left
unchanged.
This only includes the method to set the pairs of displays individually.
The functions to write a single 16 or 32 bit value have not been
implemented yet, nor has the mask function.
