Hi all,

I need to understand southbridge related code in linux source code.
For that I have downloaded Linux source code version:2.6.28 .
I have seen the code but didn't find code specific to southbridge handling.
Is Linux source code contains southbridge specific code?If so where can I find the code?

Can anyone help me to solve this? Please bear in mind that I am new to this .

Thanks in advance.

Southbridge initialization is usually done by the BIOS.

Most southbridge devices are PCI devices, i.e., they are handled by the appropriate PCI drivers.
Do you have some specific southbridge in mind?

Hi Cladisch,

Thanks for your quick reply.

As you said most of the southbridge devices are pci devices, corresponding pci drivers of linux handle those devices.

I have some doubts regarding southbridge initialization.
Is bios handles complete southbridge chipset initialization?If so what Bios does to initialize southbridge?

Read the manual of the respective southbridge.
In most cases, this involves initializing the I/O interrupt controller, configuring any PCI or PCI-E channels that are present on the motherboard, and enabling or disabling any devices that are or are not connected to some jack or helper chip on the motherboard.

I have a doubt regarding this southbridge initialization.

Some how i have loaded the OS with out initializing the Southbridge during BIOS.
Then the linux PCI drivers of Southbridge devices will work as normal as they work under general condition?
If not whether the linux PCI drivers will work when include SB initialization in the linux kernel?

Southbridge initialisation is actually a vague term.
The BIOS talks to the Southbridge, and the system has to find the disks connected to the Southbridge. If this is true to form, the pc spec will specify a way for the bios to do this, and to be pc compatible, a system will have to answer that approach on power on. Like, for example, the video comes up at 640x480 @60hz
Some time during the boot process, the kernel fine tunes everything using the drivers at it's disposal. You will see numbers being sent to registers, and you'd need the data sheet to figure it out. There is actually huge significance in these numbers. Get some data sheet for a Southbridge. Grab a kernel source and cd to ~/drivers/ide. Grok some of the code by Vojtech Pavlik. He writes well commented code and is an experienced programmer with SuSE. If you need to make sense of something, that is the way to go. The rest is done by the BIOS, which is 2MB of Assembler (Or uncommented C if you are very lucky)!

This is not possible on standard hardware.

Again, this depends on what devices in the southbridge are to be used.

Hi,

To the OP; Look at 'BIOS'.

You need to understand that the 'BIOS' does initialize the hardware. If the Linux kernel supports the hardware then appropriate drivers are used to refine or use the hardware. Sometimes the Linux kernel will use the driver without interface/use of the 'BIOS'.

Not all legacy chipsets are supported and if the chipset is to new it may utilize a extended driver/module if at all. If you have questions about a specific chipset then check the '.config' of a particular kernel.