The kernel already includes device drivers for the on-chip serial and ethernet ports.
For helpful MPC8xx-specific device driver examples, see http://lists.linuxppc.org/listarcs/linuxppc-embedded/200001/msg00221.html
ftp://ftp.denx.de/pub/LinuxPPC/usr/src/CDK.tar.gz
A flash driver will give you access to /dev/flash devices, which are useful during development and for field upgrades and are ideal for storing fixed size persistent configuration data like your board's Ethernet MAC address. This is true for drivers supporting a number of vendors' devices.
The flash driver does auto-erase when the length of data written per write() is exactly the corresponding erase block size. So usually you just need to do:
open (/dev/flash???) lseek(specific erase region) write(data, region size) |
http://qslinux.org and ftp://qslinux.org
QSLinux contains a fully functioning FLASH driver, and an interface to the Ext2FS filesystem, with compression.
http://www.linux-mtd.infradead.org/
The MTD subsystem offers a more general solution which allows you to treat the flash as a regular block device on which you can mount a filesystem. It's ideal for large amounts of variable sized data or applications requiring a traditional writable filesystem, provided by the Journaling Flash Filesystem.
However, some work is required to get the MTD to run on PowerPC, as it does not yet support big endian.
http://www.linux-mtd.infradead.org/doc2000.html
This is supported via the Memory Technology Device Subsystem.
For a PCMCIA driver, see http://lists.linuxppc.org/listarcs/linuxppc-embedded/200002/msg00093.html
There are also some fairly detailed notes available at ftp://ftp.absoval.com/pub/rpxlite/ and http://lists.linuxppc.org/listarcs/linuxppc-embedded/200005/msg00227.html
For generic Linux PCMCIA info, see http://pcmcia.sourceforge.org/ftp/doc/PCMCIA-PROG.html
There are lots of options for connecting IDE drives. You need to at least configure CONFIG_BLK_DEV_IDE and CONFIG_BLK_DEV_IDEDISK. Search for IDE.
Also, see http://www.bluebutton.com/proj/mbxlinux/
Using the on-chip watchdog to provide the basic "write kicked" /dev/watchdog interface described in Documentation/watchdog.txt is problematic, because the SYPCR register controlling it can only be written once after reset to both set the timeout and enable the watchdog. Once enabled, the boot loader and kernel must keep it from expiring up until the point where the user application opens /dev/watchdog. Littering the generic kernel decompress and startup codes with watchdog kicks to do this isn't acceptable to other Linux users. Hence, hardware watchdog support hasn't been implemented yet.
The general plan to solve this problem is described in http://lists.linuxppc.org/listarcs/ linuxppc-embedded/199910/msg00026.html
You can probably use Linux's software watchdog in the meantime.
http://www.honeywell.se/inu/usb/
These devices can be made to operate as a USB host or slave. Search for USB.
Also see the Programming Guide for Linux USB Device Drivers at http://usb.in.tum.de/ usbdoc/
Use something that "frames" the data and the SI/TDM interface works really sweet. Take a look at the CS4218 audio codec driver for the Embedded Planet boards. It's floating around in the 2.2.13 kernels on the MontaVista site.
Numerous VME board vendors offer Linux support through software partners such as Denx.
Some older patches and tarballs to use Linux on VME boards and simplify the access to the VME bus are available at ftp://vlab1.iram.es/ pub/linux-vme/
http://qslinux.org/docs/snmc/hdlc/index.html
Provides support for the HDLC protocol, running the PPP layer in order to transport IP packets across a synchronous serial link.
This driver is an interface for the SPI controller in MPC8xx. The driver is written to work with the microcode patches to correct the parameter RAM problems. The driver supports basic init, open, close, read, and write functions.
http://www.gcom.com/home/linux/lis/
LiS is a software package that comprises an implementation of SVR4-compatible STREAMS for Linux in the form of a loadable kernel module.
A patch to port it to MPC8xx based Embedded PowerPC systems is available at ftp://ftp.denx.de/pub/LinuxPPC/usr/src/LiS/