[LinuxBIOS] [PATCH] pci_rom.c checksum extension rom
Uwe Hermann
uwe at hermann-uwe.de
Thu Oct 25 18:43:01 CEST 2007
On Wed, Oct 17, 2007 at 11:30:30AM +0200, Stefan Reinauer wrote:
> > > Is this checksum reliably correct? I am hesitating to add new
> > > restrictions that might break otherwise working cards.
> >
> > You are right, attached is a correct method. There is no fixed checksum
> > byte, instead the whole should sum to zero.
>
> > --
> > Alex
> >
>
> > Signed-off-by: Alex Beregszaszi <alex at rtfs.hu>
>
> Acked-by: Stefan Reinauer <stepan at coresystems.de>
>
>
> > Index: device/pci_rom.c
> > ===================================================================
> > --- device/pci_rom.c (revision 494)
> > +++ device/pci_rom.c (working copy)
> > @@ -33,6 +33,8 @@
> > unsigned long rom_address;
> > struct rom_header *rom_header;
> > struct pci_data *rom_data;
> > + unsigned int i;
> > + unsigned char sum = 0, *rom_bytes;
> >
> > if (dev->on_mainboard) {
> > /* In case some device PCI_ROM_ADDRESS can not be set
> > @@ -67,7 +69,17 @@
> > le32_to_cpu(rom_header->signature));
> > return NULL;
> > }
> > +
> > + /* checksum */
> > + rom_bytes = (unsigned char *)rom_address;
> > + for (i = 0; i < rom_header->size * 512; i++)
> > + sum += *(rom_bytes + i);
> >
> > + if (sum != 0) {
> > + printk(BIOS_ERR, "Incorrent Expansion ROM checksum (%02x != 0)\n", sum);
> > + return NULL;
> > + }
Doesn't this mean it'll abort upon incorrect checksum? If so, NACK.
This should be a warning only, and not abort execution.
If it's implemented as warning only (without aborting):
Acked-by: Uwe Hermann <uwe at hermann-uwe.de>
Uwe.
--
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