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Difference: BigDisk (r5 vs. r4)
With an Archos, it is possible to replace the harddisk with e.g. a 160 GB model, but out of the (Rock)box, only up to 137 GB can be used.
ATA disks have an architecture limit at 137 GB, resp.128 GiB, resulting from LBA 28 bit sector addressing. Larger disks use an ATA6 extension called BigLBA or LBA48 to overcome this. Without this extension being used, the disk appears to have 137GB for compatibility reasons.
Two obstacles prevent easy use of the full capacity in an Archos:
Rockbox can now be compiled with the option HAVE_LBA48 to overcome the software issue. Because of the USB problem, the way to go is a second partition for the higher part. Rockbox has another compile option, HAVE_MULTIVOLUME, to enable working with a second partition. Only Rockbox can access it up there, not the USB mode. You either have to copy files to it before installing the disk into the Archos, or let Rockbox do it with its cut/copy/paste capabilities (slow).
Sorry, you better be able to compile Rockbox. The two options are not compiled in by default, because Rockbox would grow unnecessary for many users who have no benefit from it. At the bottom I've published links to ready-to-go custom builds in my webspace, so users who don't want to compile can try it out, but I don't want to make a habit of updating that.
Depending on what model you have (Player, FM, Recorder V1 or V2), edit the proper config file (config-player.h, config-fmrecorder.h, config-recorder.h, config-recorderv2.h) and add the following 2 lines:
Make a fresh build as usual and install it to the box. Everything should behave normal, no visible change yet.
If the disk is new, you can use the USB mode of the Archos to create the first partition as large as LBA28 allows. (If you already possess it, you probably have done so already.) If done externally, care must be taken that the partition really stays below 128 GiB, to be completely accessible!
The second partition has to be partitioned outside of the Archos, as of now. Maybe one day there will be an fdisk+format plugin so this can be done within Rockbox...
You can use such a cheap 2.5" to 3.5" adapter to connect it to your PC's IDE port, or a USB case/adapter. Create a primary partition in the free space, format it with FAT32, give it a nice volume label (optional). Don't create an extended partition, Rockbox can't use that. While you have it so nicely accessible, copy your all time favorite files (or whatever you want there) onto the second partition. Once back in the Archos, transfer to/from the second partition won't be so comfortable any more.
OK, put the disk back in your Archos and fire it up.
The second partition will appear in the Rockbox browser as a "virtual subdirectory" named <HD1>. This name is hard coded atm (for HD0 being the normal root, HD1 the next partition), maybe one day it could be the volume name. You will find its root directory under there. Ondio users already know the concept, from the external MMC card accompanying the internal storage.
Apart from this "decoration", you can do everything you want at the second partition like with the first, read and write, no limitations. The cut/copy/paste functionality is useful to move things around. It is in the context menu of the browser, hold "play" to get there. Bear in mind that if you move files across partitions, they have to in fact be copied. This is handled transparent to you, but of course way slower than just changing a directory link.
Some care must be taken in USB mode. The second partition is not reachable (as mentioned), but Windows tries to. Probably the addressing wraps into the lower part and it reads garbage. Windows suggests to format the partition, don't agree to that! I'm not sure what happens, but likely it would overwrite parts of the first partition instead.
You can hide the second partition from Windows, by changing its type from 0x0C (LBA mapped FAT32) to 0x1C (same, but hidden). This is still possible with the disk inside the Archos, because the partition table is in the very first sector of the disk, the MBR (master boot record). I did that hardcore, with a sector editor, changing the byte at offset 0x1D2 of the MBR. (Hints for nice free partitioning tools are welcome.)
Here are I have created builds from Dec 30th, 2006 for of Nov. 9, 2007 with the various Archos models: lba48 defines compiled in. They are attached. Be aware that I had to remove database since the firmware would have been too big if I havn't.
Outdated as I write this, you really better build your own.
Some potential improvements are left to us developers:
r9 - 05 Oct 2013 - 05:44:46 - HaydenPearceRevision r5 - 10 Nov 2007 - 14:33 - HarrisonTu
Revision r4 - 02 Jan 2007 - 17:16 - JoergHohensohn
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