Everdrive SDK / SD card IO

megatron-uk · 03/19/2014, 06:03 PM

I'm afraid the get next sector code isn't implemented yet.

MooZ · 03/19/2014, 06:57 PM

Good news!
I managed to make disk_write_single_sector work. But there's something weird.
Right after sending the 512 bytes, you write the 2 bytes CRC and read some kind of status. If you do a bitwise and with $1f and get 5, the write is supposed to be ok. Then you wait for the end of the transfer (which is something like while(spi_reg != 0xff) { nop; }).
But in my case, I'm getting $ff when I'm reading the write status...

MooZ · 03/24/2014, 04:29 PM

Long live to Microchip engineers! Thanks to their PIC code, I managed to fix Single Sector write.
Next is Multiple Sector writes.

megatron-uk · 03/24/2014, 05:06 PM

That sounds as though it was a hardware bug with write support? Is that the case?

If so, then bloody well done for figuring that out!

MooZ · 03/25/2014, 09:01 AM

It's not a hardware bug. It's just that sd cards are a little bit picky about writing.

MooZ · 01/01/2015, 04:09 PM

Multiple sector writes are finally working! I still need to add the C "export".
By the way, I tried to compile with the "new" HuC and it's complaining about long lines and some other weird stuffs (why were the underscore removed from _si, _cl and co?).

NightWolve · 01/01/2015, 04:47 PM

Heya Moozy.

'fraid I don't see Megatron posting much anymore, might want to PM him. He went from most prolific updater to MIA.

MooZ · 01/01/2015, 05:00 PM

Blame kids and xmas

megatron-uk · 09/15/2015, 08:00 AM

Hey all,

I've just spent a few hours working on the Everdrive-fat libraries over the past couple of days (where has the time gone???).

I've refactored a few things as well as added some missing 32bit math functions I needed (subtraction, for one). It should be easier to follow now.

I too had a problem using the later versions of huc and pceas, so I've gone back to the 3.21 release. A shame, as the new version with struct support would have made things a lot more compact (all the free fat drivers out there are ansi-c and use structs extensively).

Anyway, I'm now working on the get-next-cluster and get-next-sector code, so reading the entirety of a file from the SD card should not be far off.

Everything is on github, as usual: https://github.com/megatron-uk/everdrive-fat

trapexit · 09/15/2015, 09:54 AM

QuoteI too had a problem using the later versions of huc and pceas

What problems? Best to try and get them addressed.