Network Driver Updates for Linux kernels 1.2.0 through 2.2

Index

• Release Information
• Using the Source RPM Package
• Installing Individual Drivers
• Using These Drivers with CardBus

Release Information

This update contains two components:

• A major update for most of the PCI network drivers
• A device scan layer (See the PCI Scan) that allows a single driver to support PCI, hot-swap-PCI and CardBus hardware.

Using the Source RPM Package

The updated drivers are best installed by using the source RPM to create a custom binary RPM with kernel modules for your system:
ftp://ftp.scyld.com/pub/network/netdriver-2.1.src.rpm

Use the following commands to install and test the driver pack:

The --force option is needed because the new drivers may conflict with the existing drivers installed by the kernel package. If this occurs you will see a warning message for each driver that has been updated.

Installing Individual Drivers

Drivers may be updated individually by following the directions in http://scyld.com/expert/modules.html. You will need to build both the driver.o and pci-scan.o modules using the following source files from ftp://ftp.scyld.com/pub/network/

• the driver source file
• pci-scan.c
• pci-scan.h and
• kern_compat.h

In the instructions below driver.c refers to the name of the driver source file for your device e.g. 3c59x.c, and driver.o refers to the compiled driver binary module.

• Copy the driver source files to a convenient directory. I usually use /usr/src/modules/.
• Compile both the driver file and pci-scan.c using the compile-command at the bottom of the source files. If a compile-command is not there use the following compile command: gcc -DMODULE -D__KERNEL__ -O6 -c driver.c gcc -DMODULE -D__KERNEL__ -O6 -c pci-scan.c
• As 'root', test the module by doing insmod pci-scan.o insmod driver.o
• Install the modules in the proper location for your distribution. This is usually /lib/modules/kernel-version/net/driver.o. The command to do this is install -m 644 pci-scan.o driver.o /lib/modules/`uname -r`/net/ The uname -r command expands to the current kernel version name.

Special instructions for Red Hat 7.0

Red Hat 7.0 has a flawed configuration with their default install. It uses the header files from an unreleased 2.3.99 kernel, rather than installing the header files from the kernel that is actually running. This was an attempt to make user-level binaries independent of the specific kernel version, but it makes it impossible to automatically build kernel modules.

A second problem is that 7.0 provides an experimental version of gcc that was not intended for public release. The stable version of gcc needed to correctly compile the kernel has been renamed to kgcc.

The work-around is to substitute kgcc for gcc and to add -I/usr/src/linux/include on the compile command line when compiling by hand. The Makefile in the tar file and RPM automatically include this compile flag, however they cannot automatically use 'kgcc'.

To repeat: this is a flaw that was introduced with Red Hat 7.0. It is a Red Hat configuration problem, not a driver update distribution bug. The symptom of this bug is compile error messages such as

Building updated drivers into the kernel

The updated drivers may be also be linked into the kernel, rather than being used as a module that is linked later. Replace the drivers in drivers/net/* with the updated driver list.

Most kernel versions do not natively support the pci-scan.c layer. You will have to explicitly add pci-scan.o to the L_OBJS entry in drivers/net/Makefile.

Note that as of December 2000 the 2.4 kernel has not been released, and thus is not supported.

Using the driver update with CardBus

The new driver structure is designed for in-kernel support of CardBus and hot-swap-PCI. The in-kernel implementation in the 2.3.* kernel is still unreliable, and few hot-swap PCI implementations exists, so most users will using the PCMCIA package from David Hinds with CardBus adapters. (Ref. ftp://sourceforge.org/pcmcia/*)

Using the new drivers with the existing PCMCIA package requires the PCI driver management module, pci-scan.c, and a CardBus-specific shim module named cb_shim.c.

These new modules, along with the drivers, should be compiled using the Makefile and the resulting *.o files installed in /lib/modules/'uname -r'/pcmcia/ with the make install. The following configuration lines should be added to /etc/pcmcia/config.opts and the PCMCIA system restarted with the new configuration.

Discussion of the new driver structure

From the casual user perspective, the change to the new PCI scan code only adds complexity. Instead of each driver being a single self-contained file, you must now deal with two new header files, kern_compat.h and pci-scan.h, and a support module, pci-scan.c. For CardBus or hot-swap-PCI use an additional shim module, named cb_shim.c for CardBus, is used to enable translate power management and removal events.

The benefits of the new driver generation are subtle

• PCI scans, previously duplicated in each driver, are now done by a more sophisticated routine in pci-scan.c. The PCI bus and associated "resource" (IRQ and bus address mapping) management has been the target of frequent interface changes. Especially with the over-engineered and pointlessly complex restructuring in 2.3.13, it was being increasingly difficult to update, test and requalify drivers. This scan code, while primarily intended to extract common code, also removes many of the kernel version dependencies.
• The new PCI scan utility is table based, which concentrates the card detection information and makes it trivial to add support for new device IDs. OEM devices that are customized with unique PCI ID numbers require only an additional table entry, with little source and binary size impact.
• Drivers now natively support CardBus and hot-swap PCI, rather than having to be compiled explicitly to support either PCI or CardBus.
• ACPI (properly called PCI power management) power state utilities are available, with activation to ACPI D0 state by default.
• The utility routines in pci-scan.c work with all classes of PCI and CardBus devices, not just network cards.
• Driver source code is smaller and more readable by having the kernel version compatibility issues migrated to a header file, kern_compat.h.
• For performance reasons most drivers (exceptions: ne2k-pci and via-rhine, which have boards types with no memory space mapping) now use PCI memory space access instead of I/O space. The diagnostic routines continue to use I/O space access.
  http://www.scyld.com/diag/index.html
  ftp://ftp.scyld.com/pub/diag/