[LinuxBIOS] #57: libusb host program for PLX NET20DC debug device
yinghai.lu at amd.com
Fri Dec 1 23:10:59 CET 2006
From: ebiederm at xmission.com [mailto:ebiederm at xmission.com]
Sent: Friday, December 01, 2006 1:15 PM
Peter Stuge <stuge-linuxbios at cdy.org> writes:
>> On Fri, Dec 01, 2006 at 11:19:16AM -0800, Greg KH wrote:
>>> Well, earlyprintk will not work, as you need PCI up and running.
>> Not all of it though. LinuxBIOS will probably do just enough PCI
>> setup to talk to the EHCI controller and use the debug port _very_
>> soon after power on.
>Right. For LinuxBIOS not a problem for earlyprintk in the kernel
>somethings might need to be refactored. The challenge in the kernel
>is we don't know at build to how to do a pci_read_config...
Otherwise printk will come too late, and will not get output before pci
bus ops is set.
>The other hard part early in the kernel is the fact that the
>bar is memory mapped I/O. Which means it will need to get mapped
>into the kernels page tables.
several entries to map 0xfc000000 ( PCI IO mem range) in page table in
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