Generic OMAP port setup information (Rev #8)

Getting a ROM image and !Boot sequence

The first thing to do is obviously to get a ROM image. If you want to build one yourself, view the instructions on this page. If you want to use a prebuilt ROM image, you can download one from this page.

You may also want to download the HardDisk4 archive which contains the RISC OS 5 !Boot sequence and other utilities. Note that there are two versions available – a self-extracting version and a tar/bz2 version. Only choose the tar/bz2 version if you have a working RISC OS machine which you can use to extract the archive onto a USB device!

Putting the ROM image onto an SD card

Attempting to prepare an SD card manually can often result in failure, either due to user error or operating system quirks. The easiest way to solve this problem is to use the SDCreate utility, a copy of which is supplied with every OMAP3 ROM image distributed by ROOL. Even if you don’t have a RISC OS machine on which to run SDCreate, you’ll still want a copy of the app, as it contains a description of how SD cards are prepared, and copies of the required U-Boot scripts.

Before preparing your SD card, you may need to track down some extra files/software:

• BeagleBoard-xM users will need suitable copies of x-loader and U-Boot. You will find suitable versions on the Linux SD card that came with your board; the ‘mlo’ file is x-loader, and the ‘u-boot/bin’ file is u-boot. Alternatively, you can download the latest copies of those files from the beagleboard.org website.
• TouchBook users will need suitable copies of x-loader and U-Boot as well. You can either copy these off of the Linux SD card that came with the machine, or download new versions from the Always Innovating website.
• TouchBook users will also need a copy of the ‘mkimage’ tool that is supplied with the U-Boot sources. RISC OS users can install the RISC OS port of mkimage that is available from riscos.info. Linux users may have to build the tool from source.

Using SDCreate

The SDCreate main window is split into two sections – ‘Create image’ and ‘Write image’. Depending on which options are selected the ‘Run’ button at the bottom may or may not be greyed out.

WARNING

The code which writes images to SD cards hasn’t received thorough testing, and doesn’t ask for confirmation before beginning the write operation. So if you’ve selected the wrong drive you will lose all your data on that drive, and if you try interacting with the drive while the write is occuring then it will likely result in a corrupt image.

WARNING

If you want to create an image, and save it as a file:

• Select ‘Create image’
• Deselect ‘Write image’
• Select the right machine type
• Drag the RISC OS ROM image to the ‘ROM image’ box
• Drag the x-loader and U-Boot binaries into the x-loader and U-Boot boxes, if necessary
• Click ‘Run’

If you want to create an image, and write it straight out to a card:

• Select both ‘Create image’ and ‘Write image’
• Select the right machine type
• Drag the RISC OS ROM image to the ‘ROM image’ box
• Drag the x-loader and U-Boot binaries into the x-loader and U-Boot boxes, if necessary
• Select the SCSI drive number which your SD card reader has appeared under
• Click ‘Run’

If you want to write an existing SD image to an SD card:

• Select ‘Write image’
• Deselect ‘Create image’
• Drag the image file to the ‘SD image’ box
• Select the SCSI drive number which your SD card reader has appeared under
• Click ‘Run’

That’s it! If it all went well, you should now have a working SD card/image for use with your OMAP3 machine.

Windows/Linux/Mac/etc. utilities for writing SD card images

If you’re able to use SDCreate to create an image file, but are unable to use it to actually write the image to a card, then you can use any number of Windows/Linux/Mac utilities to do the job for you:

• Windows – Win32DiskImager
  • Just make sure the file has a .img extension for Win32DiskImager to find it
• Linux – UNetbootin
  • Or if you’re feeling adventurous, just use ‘dd’
• Mac – Installing MeeGo on your netbook
  • I’m not aware of any user-friendly utilities to do this on a Mac OS X machine, but the above instructions for writing a MeeGo Linux disc image onto a USB drive can easily be adapted for writing the SD card images created by SDCreate.

Creating SD cards manually

If you’re unable or unwilling to use SDCreate to create an image for you, then you can always create one manually. See the SDCreate !Help file for information about the SD card structure and how booting works, or alternatively this archived copy of an earlier version of this page, which contains information about a variety of different boot methods.

Putting the HardDisc4 image onto a USB drive

The OMAP3 port of RISC OS doesn’t yet contain a suitable driver to allow RISC OS to interact with the SD card slot. So your !Boot sequence must be placed on a USB drive instead. Here’s a brief guide of how to set up the drive:

If you have an existing RISC OS device with USB support

1. Format the USB device for use with RISC OS (e.g. RISC OS 5 users would use !SCSIForm)
2. Extract the HardDisk4 tar archive to the device using !UnTarBZ2 (!UnTarBZ2 is available from the same page as the HardDisk4 archive)

If you don’t have an existing RISC OS device with USB support

At the moment the only way to get around this problem is to get your OMAP3 machine (running RISC OS) to set up the boot sequence itself. Unfortunately a couple of bugs and limitations in RISC OS mean that this is currently slightly trickier than it could be, but the following should save you some time!

• First off, make sure you have a FAT formatted USB device which is formatted to under 2GB in size. If you want, this can be the same device that you’ll extract the boot sequence to, but it doesn’t have to be.
• Copy the self-extracting HardDisk4 archive onto the device, and boot your OMAP3 machine into RISC OS.
• Copy the following code into the named files and save them to the device. Ensure you include a blank line at the end of each file.
• Set their filetypes, as indicated below.

ramdisc TaskExec (&fd6)

scsi

basic

10DIM code% 256

20P%=code%

30[ OPT 0

40SWI “OS_EnterOS” 

50MRC CP15,0,R0,C1,C0,0

60BIC R0,R0,#2

70MCR CP15,0,R0,C1,C0,0

80MSR CPSR_c,#&10

90MOV R0,R0

100MOV PC,R14

110]

120CALL code%

SAVE"AOff"

QUIT

changedynamicarea -ramfssize 32m

ram

| *******************************

| * Wait for RAM Disc to appear *

| *   before running ‘extract’  *

| *******************************

|

extract Obey (&feb)

scsi

filer_opendir RAM::RamDisc0.$

settype SCSI::0.HardDisc4/util &ffc

copy SCSI::0.AOff RAM::RamDisc0.$.AOff ~c

copy SCSI::0.HardDisc4/util RAM::RamDisc0.$.HardDisc4/util ~c

filer_run RAM::RamDisc0.$.HardDisc4/util

|

• Run ‘ramdisc’¹
• When the RamDisc appears, run ‘extract’
• Once extracted, use HardDisc4.Utilities.USB-Mass.!SCSIForm to reformat the drive that you ultimately want the boot sequence to reside on.
• Once reformatted, simply copy the contents of the HardDisc4 folder to the USB drive.

¹ Note that there’s currently a bug that will cause RAM disc creation to fail. As a workaround, the BASIC program listed here is run to disable alignment exceptions before trying to create the RAM disc. (This file is also saved to disk. You’ll probably wan’t to keep it for future use as required by some programs at the moment.)