Writing to eMMC

LeafDerekson

I have gotten a little over my head. I think I erased the eMMC. I meant to delete my SD card and load a new bela disk image on it. When the card was empty and the unit was connected to my computer I could see a drive named BeagelBoard. I thought I simply ejected it but now when I plug the bela into my computer the drive doesn't pop up. I could the device in disk utility but it says it was empty. I got the new BBB disk image, the one that will flash the eMMC on boot, and have ran that so that the BBB disk image is in the eMMC. I have been on the BeagleBoard forum and they say that I dont need the BBB disk image on the EMMc I need the bela image. I thought I needed to but the BBB disk image on the eMMC and the Bela on the SD card. Am I doing this right? Sorry if some of my technical vocab is unclear. I'm learning a lot.

giuliomoro

LeafDerekson I have been on the BeagleBoard forum and they say that I dont need the BBB disk image on the EMMc I need the bela image.

that's correct. So now yo need to delete it and replace it with the Bela image. Make sure you have a Bela-flahsed SD card and then Follow the instructions here, you probably have to go through Option 3 and Common steps there.

LeafDerekson

Thanks. I've done did that. Now I'm at the part about backing up the SD card then copying the SD card to the eMMC. Do I want to do this? I skipped ahead to the resize SD card and have done that successfully.
After that, there is the section "Accessing the Other Card". Im sure this is the part I need but I don't understand the section well.
I want to record audio onto the SD card with [writesf~]. When I do this on my computer it works great. But on Bela, the first file will open but my patch fails before the second recording starts. The message says it is makefilename. Since doing these steps and loading the latest version of Bela I don't get an error but I don't get a file either. I'm sure that the problem is I don't know where to set the location for the file. Is that clear? For example, this is what I am sending into [makefile]:
[counter] [set /Volumes/BELABOOT/RECORD/myfile-%d.wav(
| |

[makefilename myfile-%d.wav]
[open -byte 3 $d(
|
[writesf~]

giuliomoro

LeafDerekson After that, there is the section "Accessing the Other Card". Im sure this is the part I need but I don't understand the section well.

You want to run this /opt/Bela/bela_flash_emmc.sh once to flash the Bela image on the eMMC. Once that is done, you can decide whether you want to use the image from the SD card or from the eMMC (it will boot from the SD card if there is a valid image on it). If you skip that step, you may have trouble at each boot.

LeafDerekson [set /Volumes/BELABOOT/RECORD/myfile-%d.wav(

that is the path of the partition on your mac, but from Bela, it would be at a different place, probably /mnt/boot/RECORD/myfile-%d.wav. However, I would strongly discourage you to write to that partition. First off, it is a very small partition (~70MB if I remember right). Secondly, if the partition gets corrupted, you won't be able to boot the board.

LeafDerekson After that, there is the section "Accessing the Other Card". Im sure this is the part I need but I don't understand the section well.

If what you are trying to do is what you wrote here, then maybe the best option is probably to boot your board from the eMMC, and use a FAT32-formatted SD card (or USB stick) for accessing those data, so that you can then later access that drive from your mac. See here for instructions on that.

LeafDerekson

Alright, I have the Bela running from the eMMC and my sd card configured and mounted as the instructions say. Now, the only thing I dont know is what to put into [set myfile-%d.wav(. I named the partition SRSA after the project. Do I set the name as [set /mnt/SRSA/myfile-%d.wav(? Once I learn this part will everything work? Right now I'm getting an error message which says:
CPU time limit exceeded
make: *** [runide] Error 152

The error happens when the stop message bangs [writesf~]

Thanks for your time.

giuliomoro

LeafDerekson Do I set the name as [set /mnt/SRSA/myfile-%d.wav(?

If the partition is automatically mounted at /mnt/SRSA/, then this seems right.

LeafDerekson Once I learn this part will everything work?

ehmmm... I don't know ?

LeafDerekson Right now I'm getting an error message which says:
CPU time limit exceeded
make: *** [runide] Error 152

The error happens when the stop message bangs [writesf~]

Hmm... this is interesting. It means that it took more than 4 seconds busy trying to do something ... it doesn' t seem right. Can you test it with a very short file? Also, can you share a minimal patch that reproduces the issue?

LeafDerekson

Ok. I have composed 5 responses then deleted them. When I use [set /mnt/SRSA/myfile-%d.wav( everything works perfect but I removed the sd card and put it in my computer and I dont see any files in SRSA. I was just about to eject the SD card and noticed in my finder that the Belaboard tab is filled with myfile#.wav recordings. I have figured out that when I run my patch without the sd card the files still write to the eMMC.

So, something has worked. But I'm still confused. I must have made a mistake when setting up the card as in the Accessing a USB/SD article.
alt text

giuliomoro

Can you show the contents of /etc/fstab on your board?

LeafDerekson

I re-did everything in the accessing instructions. I must have made a typo in the name while making the partition because things are smooth now.
Thank you