LinuxPPC-Dev Archive on lore.kernel.org
 help / color / mirror / Atom feed
* Questions about PCI resources in Linux 2.4.25 for MPC8260
@ 2004-11-25  9:59 Laurent Lagrange
  0 siblings, 0 replies; only message in thread
From: Laurent Lagrange @ 2004-11-25  9:59 UTC (permalink / raw)
  To: linuxppc-embedded


Hi,

I ported a MPC8260 custom LSP from Linux 2.4.18 to Linux 2.4.25 and
I discovered something strange in the last kernel.

In the file arch/ppc/kernel/setup.c, the function "setup_arch" runs this new
code :

    code_resource.start   = virt_to_bus((void *)PAGE_OFFSET);
    code_resource.end    = virt_to_bus(&_etext)-1;
    data_resource.start   = virt_to_bus(&_etext);
    data_resource.end    = virt_to_bus(&_edata)-1;
    request_resource(&iomem_resource, &code_resource);
    request_resource(&iomem_resource, &data_resource);

This code seems to reserve PCI resources for the kernel code and data.

Has anybody an idea why these resources are added and needed ?
To detect future PCI conflicts ? To preserve from external PCI accesses ?

If the board sdram is not mapped on PCI at 0x00000000, these resources
generate problems when scanning pci bus and discovering sdram space
in own pci bridge header space.

Is there a new rule to set sdram board to 0x00000000 instead of 0x80000000
while enumerating PCI.

Thanks for your ideas.
 Laurent

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2004-11-25 20:51 UTC | newest]

Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2004-11-25  9:59 Questions about PCI resources in Linux 2.4.25 for MPC8260 Laurent Lagrange

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox