| The Intel Assabet (SA-1110 evaluation) board | |
| ============================================ | |
| Please see: | |
| http://developer.intel.com | |
| Also some notes from John G Dorsey <jd5q@andrew.cmu.edu>: | |
| http://www.cs.cmu.edu/~wearable/software/assabet.html | |
| Building the kernel | |
| ------------------- | |
| To build the kernel with current defaults: | |
| make assabet_config | |
| make oldconfig | |
| make zImage | |
| The resulting kernel image should be available in linux/arch/arm/boot/zImage. | |
| Installing a bootloader | |
| ----------------------- | |
| A couple of bootloaders able to boot Linux on Assabet are available: | |
| BLOB (http://www.lartmaker.nl/lartware/blob/) | |
| BLOB is a bootloader used within the LART project. Some contributed | |
| patches were merged into BLOB to add support for Assabet. | |
| Compaq's Bootldr + John Dorsey's patch for Assabet support | |
| (http://www.handhelds.org/Compaq/bootldr.html) | |
| (http://www.wearablegroup.org/software/bootldr/) | |
| Bootldr is the bootloader developed by Compaq for the iPAQ Pocket PC. | |
| John Dorsey has produced add-on patches to add support for Assabet and | |
| the JFFS filesystem. | |
| RedBoot (http://sources.redhat.com/redboot/) | |
| RedBoot is a bootloader developed by Red Hat based on the eCos RTOS | |
| hardware abstraction layer. It supports Assabet amongst many other | |
| hardware platforms. | |
| RedBoot is currently the recommended choice since it's the only one to have | |
| networking support, and is the most actively maintained. | |
| Brief examples on how to boot Linux with RedBoot are shown below. But first | |
| you need to have RedBoot installed in your flash memory. A known to work | |
| precompiled RedBoot binary is available from the following location: | |
| ftp://ftp.netwinder.org/users/n/nico/ | |
| ftp://ftp.arm.linux.org.uk/pub/linux/arm/people/nico/ | |
| ftp://ftp.handhelds.org/pub/linux/arm/sa-1100-patches/ | |
| Look for redboot-assabet*.tgz. Some installation infos are provided in | |
| redboot-assabet*.txt. | |
| Initial RedBoot configuration | |
| ----------------------------- | |
| The commands used here are explained in The RedBoot User's Guide available | |
| on-line at http://sources.redhat.com/ecos/docs.html. | |
| Please refer to it for explanations. | |
| If you have a CF network card (my Assabet kit contained a CF+ LP-E from | |
| Socket Communications Inc.), you should strongly consider using it for TFTP | |
| file transfers. You must insert it before RedBoot runs since it can't detect | |
| it dynamically. | |
| To initialize the flash directory: | |
| fis init -f | |
| To initialize the non-volatile settings, like whether you want to use BOOTP or | |
| a static IP address, etc, use this command: | |
| fconfig -i | |
| Writing a kernel image into flash | |
| --------------------------------- | |
| First, the kernel image must be loaded into RAM. If you have the zImage file | |
| available on a TFTP server: | |
| load zImage -r -b 0x100000 | |
| If you rather want to use Y-Modem upload over the serial port: | |
| load -m ymodem -r -b 0x100000 | |
| To write it to flash: | |
| fis create "Linux kernel" -b 0x100000 -l 0xc0000 | |
| Booting the kernel | |
| ------------------ | |
| The kernel still requires a filesystem to boot. A ramdisk image can be loaded | |
| as follows: | |
| load ramdisk_image.gz -r -b 0x800000 | |
| Again, Y-Modem upload can be used instead of TFTP by replacing the file name | |
| by '-y ymodem'. | |
| Now the kernel can be retrieved from flash like this: | |
| fis load "Linux kernel" | |
| or loaded as described previously. To boot the kernel: | |
| exec -b 0x100000 -l 0xc0000 | |
| The ramdisk image could be stored into flash as well, but there are better | |
| solutions for on-flash filesystems as mentioned below. | |
| Using JFFS2 | |
| ----------- | |
| Using JFFS2 (the Second Journalling Flash File System) is probably the most | |
| convenient way to store a writable filesystem into flash. JFFS2 is used in | |
| conjunction with the MTD layer which is responsible for low-level flash | |
| management. More information on the Linux MTD can be found on-line at: | |
| http://www.linux-mtd.infradead.org/. A JFFS howto with some infos about | |
| creating JFFS/JFFS2 images is available from the same site. | |
| For instance, a sample JFFS2 image can be retrieved from the same FTP sites | |
| mentioned below for the precompiled RedBoot image. | |
| To load this file: | |
| load sample_img.jffs2 -r -b 0x100000 | |
| The result should look like: | |
| RedBoot> load sample_img.jffs2 -r -b 0x100000 | |
| Raw file loaded 0x00100000-0x00377424 | |
| Now we must know the size of the unallocated flash: | |
| fis free | |
| Result: | |
| RedBoot> fis free | |
| 0x500E0000 .. 0x503C0000 | |
| The values above may be different depending on the size of the filesystem and | |
| the type of flash. See their usage below as an example and take care of | |
| substituting yours appropriately. | |
| We must determine some values: | |
| size of unallocated flash: 0x503c0000 - 0x500e0000 = 0x2e0000 | |
| size of the filesystem image: 0x00377424 - 0x00100000 = 0x277424 | |
| We want to fit the filesystem image of course, but we also want to give it all | |
| the remaining flash space as well. To write it: | |
| fis unlock -f 0x500E0000 -l 0x2e0000 | |
| fis erase -f 0x500E0000 -l 0x2e0000 | |
| fis write -b 0x100000 -l 0x277424 -f 0x500E0000 | |
| fis create "JFFS2" -n -f 0x500E0000 -l 0x2e0000 | |
| Now the filesystem is associated to a MTD "partition" once Linux has discovered | |
| what they are in the boot process. From Redboot, the 'fis list' command | |
| displays them: | |
| RedBoot> fis list | |
| Name FLASH addr Mem addr Length Entry point | |
| RedBoot 0x50000000 0x50000000 0x00020000 0x00000000 | |
| RedBoot config 0x503C0000 0x503C0000 0x00020000 0x00000000 | |
| FIS directory 0x503E0000 0x503E0000 0x00020000 0x00000000 | |
| Linux kernel 0x50020000 0x00100000 0x000C0000 0x00000000 | |
| JFFS2 0x500E0000 0x500E0000 0x002E0000 0x00000000 | |
| However Linux should display something like: | |
| SA1100 flash: probing 32-bit flash bus | |
| SA1100 flash: Found 2 x16 devices at 0x0 in 32-bit mode | |
| Using RedBoot partition definition | |
| Creating 5 MTD partitions on "SA1100 flash": | |
| 0x00000000-0x00020000 : "RedBoot" | |
| 0x00020000-0x000e0000 : "Linux kernel" | |
| 0x000e0000-0x003c0000 : "JFFS2" | |
| 0x003c0000-0x003e0000 : "RedBoot config" | |
| 0x003e0000-0x00400000 : "FIS directory" | |
| What's important here is the position of the partition we are interested in, | |
| which is the third one. Within Linux, this correspond to /dev/mtdblock2. | |
| Therefore to boot Linux with the kernel and its root filesystem in flash, we | |
| need this RedBoot command: | |
| fis load "Linux kernel" | |
| exec -b 0x100000 -l 0xc0000 -c "root=/dev/mtdblock2" | |
| Of course other filesystems than JFFS might be used, like cramfs for example. | |
| You might want to boot with a root filesystem over NFS, etc. It is also | |
| possible, and sometimes more convenient, to flash a filesystem directly from | |
| within Linux while booted from a ramdisk or NFS. The Linux MTD repository has | |
| many tools to deal with flash memory as well, to erase it for example. JFFS2 | |
| can then be mounted directly on a freshly erased partition and files can be | |
| copied over directly. Etc... | |
| RedBoot scripting | |
| ----------------- | |
| All the commands above aren't so useful if they have to be typed in every | |
| time the Assabet is rebooted. Therefore it's possible to automate the boot | |
| process using RedBoot's scripting capability. | |
| For example, I use this to boot Linux with both the kernel and the ramdisk | |
| images retrieved from a TFTP server on the network: | |
| RedBoot> fconfig | |
| Run script at boot: false true | |
| Boot script: | |
| Enter script, terminate with empty line | |
| >> load zImage -r -b 0x100000 | |
| >> load ramdisk_ks.gz -r -b 0x800000 | |
| >> exec -b 0x100000 -l 0xc0000 | |
| >> | |
| Boot script timeout (1000ms resolution): 3 | |
| Use BOOTP for network configuration: true | |
| GDB connection port: 9000 | |
| Network debug at boot time: false | |
| Update RedBoot non-volatile configuration - are you sure (y/n)? y | |
| Then, rebooting the Assabet is just a matter of waiting for the login prompt. | |
| Nicolas Pitre | |
| nico@fluxnic.net | |
| June 12, 2001 | |
| Status of peripherals in -rmk tree (updated 14/10/2001) | |
| ------------------------------------------------------- | |
| Assabet: | |
| Serial ports: | |
| Radio: TX, RX, CTS, DSR, DCD, RI | |
| PM: Not tested. | |
| COM: TX, RX, CTS, DSR, DCD, RTS, DTR, PM | |
| PM: Not tested. | |
| I2C: Implemented, not fully tested. | |
| L3: Fully tested, pass. | |
| PM: Not tested. | |
| Video: | |
| LCD: Fully tested. PM | |
| (LCD doesn't like being blanked with | |
| neponset connected) | |
| Video out: Not fully | |
| Audio: | |
| UDA1341: | |
| Playback: Fully tested, pass. | |
| Record: Implemented, not tested. | |
| PM: Not tested. | |
| UCB1200: | |
| Audio play: Implemented, not heavily tested. | |
| Audio rec: Implemented, not heavily tested. | |
| Telco audio play: Implemented, not heavily tested. | |
| Telco audio rec: Implemented, not heavily tested. | |
| POTS control: No | |
| Touchscreen: Yes | |
| PM: Not tested. | |
| Other: | |
| PCMCIA: | |
| LPE: Fully tested, pass. | |
| USB: No | |
| IRDA: | |
| SIR: Fully tested, pass. | |
| FIR: Fully tested, pass. | |
| PM: Not tested. | |
| Neponset: | |
| Serial ports: | |
| COM1,2: TX, RX, CTS, DSR, DCD, RTS, DTR | |
| PM: Not tested. | |
| USB: Implemented, not heavily tested. | |
| PCMCIA: Implemented, not heavily tested. | |
| PM: Not tested. | |
| CF: Implemented, not heavily tested. | |
| PM: Not tested. | |
| More stuff can be found in the -np (Nicolas Pitre's) tree. | |