A650 working great, but what about SDHC/FAT32 support in the future? - General Discussion and Assistance - CHDK Forum

A650 working great, but what about SDHC/FAT32 support in the future?

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I just bought a few 4GB SanDisk cards for my A640, which worked quite well, but they don't work so well in my A650 (when trying to use CHDK, at least.)  This because the A650 requires a bootable card, whereas the A640 did not.

I understand that the current situation only allows for booting on FAT16 cards because of current limitations, and at least in Mac OS X, FAT16 on a 4GB card is not readily possible (at least in the hour I was hammering away in diskutil trying to get it going.)

My question is: is bootable FAT32 support a possibility in the (near?) future?  I'd like to know if I should keep the 4GB cards for non-raw shooting to be used for raw later or sell them and stock up on 2GB cards to use day-to-day.

Thank you so much for all the hard work.  I really do appreciate it!

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Offline GrAnd

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Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #1 on: 16 / February / 2008, 02:33:29 »
My question is: is bootable FAT32 support a possibility in the (near?) future?

Unfortunately, no. It's camera firmware limitation.
But there is no problem to make 4GB card bootable. If the Mac does not allow you to format it in FAT16, find a PC and format the card there.
CHDK Developer.

Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #2 on: 16 / February / 2008, 03:18:05 »
Unfortunately, no. It's camera firmware limitation.  But there is no problem to make 4GB card bootable. If the Mac does not allow you to format it in FAT16, find a PC and format the card there.

Thanks for the quick response!  What a bummer, though.  I wonder if it is a specifically planned limitation or something that is just not implemented because they didn't see a need.

I'll try Linux on Parallels first to see if that does the trick (it should.)  Main problem is that I don't know if OS X will recognize FAT16 with the larger cluster size.  I hope it does.  We'll find out soon, I guess!

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Offline whim

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Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #3 on: 16 / February / 2008, 06:14:05 »
Have you tried using format.exe in DOS Box ?

It runs on MacOS, here: http://www.dosbox.com/

wim
« Last Edit: 16 / February / 2008, 06:17:28 by whim »


Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #4 on: 16 / February / 2008, 17:29:18 »
Have you tried using format.exe in DOS Box ?

I just tried using format.exe from AXCEL216 / MDGx MS-DOS Undocumented + Hidden Secrets in DOSbox, and it wasn't very happy just trying to format a 1GB SD card.  Maybe there is a different utility for doing 64k clusters on FAT16 in DOSbox?

I'm currently installing Fedora Core 8 on Parallels right now to see if it works.  Overkill, maybe.  But if it does what I want, maybe it'll be worth it.  The big question is if OS X will read 64k cluster FAT16 disks.  Yikes!

Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #5 on: 17 / February / 2008, 02:06:49 »
FC8 was being annoying, so I resorted to using XP Pro on the fiancee's machine, and it formatted the card just fine through Parallels and a SanDisk USB reader.  OS X seems to see the volume just fine under 10.5  I'll have to shoot a card full to make sure it will be read properly, however.

Bums me out, though, that to get CHDK going on a 4GB card I _need_ to have Windows to do it.

I wonder if anyone knows how to get format a disk with 64k clusters using FAT16 in OS X?  Any ideas?  Is it even possible?

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Offline PhyrePhoX

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Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #6 on: 17 / February / 2008, 15:16:38 »
i suppose most people here do not have a mac, and if they did, they'd probably also own a DSLR :D try searching wth google for a solution to the problem. i'm sure it is possible, after all os x is based on unix, and with that - nothing is impossible :)

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Offline RyeBrye

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Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #7 on: 18 / February / 2008, 01:04:51 »
Yes. Piece of cake... I haven't done it personally, but since OS X is running on top of Unix, just about everything you can do on linux can be done on the Mac. Sometimes, it involves installing GNU tools- (darwin ports is your friend!) - but most of the time the commands are "just there"

In this case, newfs_msdos is your friend:

Code: [Select]
man newfs_msdos
Code: [Select]
NAME
     newfs_msdos -- construct a new MS-DOS (FAT) file system

SYNOPSIS
     newfs_msdos [-N] [-B boot] [-F FAT-type] [-I volid] [-O OEM]
                 [-S sector-size] [-a FAT-size] [-b block-size]
                 [-c cluster-size] [-e dirents] [-f format] [-h heads]
                 [-i info] [-k backup] [-m media] [-n FATs] [-o hidden]
                 [-r reserved] [-s total] [-u track-size] [-v volume-name]
                 special [disktype]

So... Yes, it appears you should be able to easily format a FAT16 with 64k cluster sizes on a mac in one command.

You will have to unmount the partition (don't eject it, unmount it) before creating the new filesystem on it. Once you have it in the FAT16 format, you can then use hexedit to make it bootable. (I posted notes on the wiki a little while ago about how to make a card bootable using a mac... basically... it's the same as linux - use hexedit and edit the partition)

The only thing I use Windows for is IDA pro - and that's just because their Mac / Linux version is a complete joke.



Re: A650 working great, but what about SDHC/FAT32 support in the future?
« Reply #8 on: 18 / February / 2008, 02:34:41 »
In this case, newfs_msdos is your friend
As is often the case, searching for the task doesn't always turn up the right tools.  Thank you so much!

So, the easy way to do this is to format the card on-camera.  It sets up the card as FAT32 with an MBR partition scheme.  (I'm sure it's easy to do at the command line, but I'm not as experienced as some others.)

Next step is to insert the card into the reader, and use disk utility to unmount the main partition (again, or use your preferred command line utility)

Using newfs_msdos, which is bundled with OS X 10.5 and maybe older OSes as well, you would type in:
Code: [Select]
newfs_msdos -F 16 -b 65536 disk1s1Where the "-F 16" specifies FAT16, the "-b 65536" specifies a 64KB cluster, and "disk1s1" is the partition location for what I'm looking to convert to FAT16.

Though I haven't tried it, OS X is happy reading the partition after mounting, and I'm assuming the HexEdit boot-enabling steps will work.  I'm going to bed now, but I'll try it in the morning.

Thanks for the guidance, RyeBrye!

 

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