How to build a custom RedHat Linux driver disc ---------------------------------------------- 2001, Petr Sulla, xsulla@fi.muni.cz Disclaimer ---------- RedHat doesn't provide ANY information about the driver disc (at least I couldn't find any). I found out all information written here by myself and from various sites on the Net and can't guarantee it's correctness. Please notify me, if it's buggy, if it's total nonsence ;) or if there's an easier way to do it. It worked for me, it also could work for you. Don't blame me if it doesn't. Motivation ---------- Imagine the following situation - you have a device, that is critical for installing RedHat Linux on a computer. This device is not supported by the kernel used by the installer. A good example is a RAID controller, eg. the Mylex AccelRAID 170 in RH 7.0. Now you are in a BIG trouble ;) There are two ways to install RedHat Linux on such a computer: a) temporarily attach a supported device, install Linux on it, compile the kernel with support for your device, copy ... b) build a driver disc Since the option a) is not always the easy or possible way to go, we will further investigate the option to build a custom driver disc. Structure of the driver disc ---------------------------- We will use the Mylex AccelRAID 170 SCSI controller with a RAID5 array as an example and we try to install RH 7.0 on it. The driver disc is a floppy with MSDOS file system. Mount it and list the files. ]# mount /dev/fd0 /mnt/fd0 -t msdos ]# ls -l /mnt/fd0 You should see something like this: -rw-r--r-- 1 root root 4327 Aug 31 2000 modinfo -rw-r--r-- 1 root root 766526 Aug 31 2000 modules.cgz -rw-r--r-- 1 root root 538 Aug 31 2000 modules.dep -rw-r--r-- 1 root root 2244 Aug 31 2000 pcitable -rw-r--r-- 1 root root 21 Aug 31 2000 rhdd-6.1 I try to explain what all the files mean and how to create them. modinfo ------- Contains information about avaliable modules and their parameters. It looks like this: Version 0 3c501 eth "3Com 3c501" io "Base I/O address" irq "IRQ level" aha1542 scsi "Adaptec AHA-154x and 631x-based" My guess is this: 3c501 etc. - name of the module eth, scsi etc. - type of the device "3Com 3c501" - name of the device to be shown to the user io, irq etc. - name of module parameters to be entered by the user and their description In my case, I created a file containing the following lines: Version 0 DAC960 scsi "Mylex AccelRAID 170" modules.cgz ----------- This is probably the most difficult to create file. It contains packed module files. It's a gzipped cpio archive. You can copy it to your harddrive and then decompress it by using ]# zcat modules.cgz | cpio -id It contains a single directory with the name of the kernel version used by the installer, eg. 2.2.16-22BOOT for RH 7.0. This directory contains all the modules like 3c501.o etc. Making your own modules.cgz ~~~~~~~~~~~~~~~~~~~~~~~~~~~ You need to get the source for your device's driver and compile it as module. You of course need another computer with Linux for this. When you are going to build the module, you must get EXACTLY the same kernel, that is used by the installer and compile the driver as module using this kernel. You can get this kernel by installing kernel-source*.rpm or by getting the appropriate version eg. from ftp.kernel.org. Then you have to change the kernel version in /usr/src/linux/Makefile with EXTRAVERSION=-subsublevelBOOT, eg. EXTRAVERSION=-22BOOT for the 2.2.16 kernel in RH 7.0. The compiled kernel will then have version 2.2.16-22BOOT. The version must EXACTLY match the kernel version used by the installer. In my case I needed to get the 2.2.16 kernel (used in RH 7.0) and the updated driver DAC960. Install your device driver source to the kernel sources, then configure the kernel, select the driver as module and make the modules (you can install them as well, so you can better find the compiled module). Then create a directory having the same name as your kernel version, eg. 2.2.16-22BOOT for RH 7.0. Copy the compiled module (eg. from /lib/modules/2.2.16-22BOOT) to this directory. In my case it was the file DAC960.o. Then you can create the modules.cgz out of this directory. You can do it this way: ]# ls -1 2.2.16-22BOOT/*.o | cpio -Hcrc -o | gzip -9 > modules.cgz (you must be in the directory containing the 2.2.16-22BOOT directory) Just to make things even clearer: as you probably have guessed, there could be more directories named after different kernel versions containing the module, that could be placed in modules.cgz. The driver disc could be then used in all RedHat Linux distributions. There's even a module development kit from RedHat containg kernel headers to all kernel versions used by RedHat installers, which allows to compile the module for all RedHat Linux distributions (I didn't try it). modules.dep ----------- Contains information about module dependencies, ie. what other modules a module needs. It looks like this: parport_pc: parport 3c503: 8390 plip: parport_pc I think it's quite selfexplanatory. In my case, I left this file blank, because DAC960 requires no other modules. pcitable -------- Contains vendor and device numbers of PCI cards and their appropriate device drivers. The PCI devices are identified by their vendor and device numbers, so it's important to enter them. The file looks like this: 0x0e11 0x0508 "sktr" "Compaq|Netelligent 4/16 Token Ring" 0x0e11 0xb060 "cciss" "Compaq|Smart Array 5300 Controller" 0x1000 0x0701 "yellowfin" "Symbios|83C885" 0x1000 0x0702 "yellowfin" "Symbios|Yellowfin G-NIC gigabit ethernet" 0x1011 0x001a "acenic" "Farallon|PN9000SX" where the items have this meaning: vendor no., device no., driver name, description. You have to find out the PCI vendor and model numbers for your device. This is quite easy, because you just have to boot the machine with some one-floppy distro (like tomsrtbt) and then cat the /proc/pci file or run the lspci utility from pciutils. In my case, the pcitable file looked like this: 0x1069 0x0050 "DAC960" "Mylex AccelRAID 170" rhdd-6.1 -------- Contains a single line: Supplemental Drivers Well, there must be a way to identify the driver disc ;) How to build and use the custom driver disc ------------------------------------------- Just format a floppy with the MSDOS file system using ]# mkdosfs /dev/fd0 Then create all the files as described above and copy them to the floppy. That's all. When installing, choose the 'linux dd' installation (have a driver disc). Insert the disc when you are asked to. If you did everything right, you can choose the correct driver and/or the installer recognizes your device and loads the driver. Good luck ! Links ----- http://www.tunl.duke.edu/~canon/linux/add_driver.html