Re: [LinuxBIOS] [PATCH] pci_rom.c checksum extension rom

[Uwe Hermann]

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.
> >
> > Signed-off-by: Alex Beregszaszi
>
> Acked-by: Stefan Reinauer
> > 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.