diff options
Diffstat (limited to 'docs/driverdisc.txt')
| -rw-r--r-- | docs/driverdisc.txt | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/docs/driverdisc.txt b/docs/driverdisc.txt new file mode 100644 index 000000000..507598970 --- /dev/null +++ b/docs/driverdisc.txt @@ -0,0 +1,125 @@ +Brief description of DriverDisc version 3 +========================================== + +For a new major release we decided to introduce a new version of DriverDisc +feature to ensure the smoothest vendor and user experience possible. We had +many reasons for it: + +- the old DD didn't support multiple architectures +- the old DD wasn't particulary easy to create +- the old DD had two copys of modules, one for anaconda and one for + instalation +- the modules in old DD weren't checked for kernel version + +We also changed the feature internal code to enable some functionality that +was missing from the old version. More about it below. + +Devices which can contain DDs +----------------------------- + +The best place to save your DriverDisc to is USB flash device. We also support +(or plan to) IDE and SATA block devices with or without partitions, DriverDisc +image stored on block device, initrd overlay (see documentation below) and for +special cases even network retrieval of DriverDisc image. + +What can be updated using DDs? +------------------------------ + +All drivers for block devices, which weren't used for retrieving DriverDiscs, +the same applies also for network drivers eg. you cannot upgrade network +driver for device, which was used prior the DriverDisc extraction. + +RPMs for installation. If the DriverDisc repo contains newer package, than the +official repository, the newer package will get used. + +We also plan to support anaconda's updates.img placement on the DriverDisc to +update stage2 behaviour of anaconda. + +Selecting DD manually +--------------------- + +There are two ways of triggering DD mode and loading updated drivers manually. + +The first is using 'dd=<location>' argument on the kernel command line during +installation boot. + +Second way is by using only 'dd' argument on the command line and then using +the TUI provided by anaconda to select DriverDisc's source location. + +Documentation for current release will provide more details as this wasn't +changed. + +Automatic DriverDisc detection +------------------------------ + +Anaconda can be told to look for driverdisc automatically by using 'dlabel=on' +kernel command line argument. This is enabled by default in Red Hat Enterprise +Linux version of Anaconda. + +The DriverDisc has to be on partition or filesystem which has been labeled +with 'oemdrv' label. + + +DDv3 structure +-------------- + +The new DriverDisc format uses simple layout which can be created on top of +any anaconda's supported filesystem (vfat, squashfs, ext2 and ext3). + +/ +|rhdd3 - DD marker, contains the DD's description string +/rpms +| /i386 - contains RPMs for this arch and acts as Yum repo +| /i586 +| /x86_64 +| /ppc +| /... - any other architecture the DD provides drivers for + +There is a special requirement for the RPMs used to update drivers. Anaconda +picks up only RPMs which provide kernel-modules-<running kernel version>. + +Initrd overlay driverdisc image +------------------------------- + +We have designed another possible way of providing updates in network boot +environments. It is possible to update all modules this way, so if special +storage module (which gets used early) needs to be updated, this is the +preffered way. + +This kind of driverdisc image is applied over the standard initrd and so has +to respect some rules. + +- All updated modules belong to /lib/modules/<kernel version>/.. according to + their usual location +- All new modules belong to /tmp/DD/lib/modules +- All new firmware files belong to /tmp/DD/lib/firmware +- The rpm repo with updated packages belongs to /tmp/DD-initrd/ +- The (empty) trigger file /.rundepmod must be present + +Firmware and module update +-------------------------- + +The firmware files together with all .ko files from the RPMs are exploded to +special module location, which has preference over built-in Anaconda modules. + +Anaconda doesn't use built-in modules (except some storage modules needed for +the DD to function properly) during the DriverDisc mode, so even in case when +you are updating some modules with second (or later) DriverDisc, the updated +modules will be loaded. There is one exception though, if your module depends +on a module which is only present in built-in module directory, that built-in +module gets also loaded. + +Package installation +-------------------- + +It is also possible to include arbitrary packages on the DriverDisc media and +mark them for installation. You just have to include the package name in the +Yum repo for correct architecture and mark it as mandatory. + + +Summary +------- + +This new DriverDisc format should simplify the DD creation and usage a lot. We +will gladly hear any comments as this is partially still work in progress. + |