Bug#383465: Contains obfuscated source code, DFSG violation?

Package: xserver-xorg-video-nv
Version: 1:1.0.1.5-2
Severity: serious

The nv driver appears to be heavily obfuscated and is effectively
unmodifiable. Rather than symbolic constants, almost every reference to
hardware is performed using undocumented hex. The only registers that
appear to be documented are the legacy CRTC ones which are effectively
identical over all hardware. Take for example NVBacklightEnable:

if((pNv->Chipset == 0x10DE0179) ||
(pNv->Chipset == 0x10DE0189) ||
(pNv->Chipset == 0x10DE0329))
{
/* NV17,18,34 Apple iMac, iBook, PowerBook */
CARD32 tmp_pmc, tmp_pcrt;
tmp_pmc = pNv->PMC[0x10F0/4] & 0x7FFFFFFF;
tmp_pcrt = pNv->PCRTC0[0x081C/4] & 0xFFFFFFFC;
if(on) {
tmp_pmc |= (1 << 31);
tmp_pcrt |= 0x1;
}
pNv->PMC[0x10F0/4] = tmp_pmc;
pNv->PCRTC0[0x081C/4] = tmp_pcrt;
}

The idea that nvidia do not posess an electronic list of register names
and offsets is entirely implausible. The only rational explanation is
that register information is postprocessed out in order to reduce
information leakage. The shipped code is certainly not the preferred
form for modification, and according to prevailing attitudes on
debian-legal should be removed from Debian.

--
Matthew Garrett | mjg59.DeleteThis@srcf.ucam.org


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On Thu, Aug 17, 2006 at 02:12:17PM +0100, Matthew Garrett wrote:
> The nv driver appears to be heavily obfuscated and is effectively
> The idea that nvidia do not posess an electronic list of register names
> and offsets is entirely implausible. The only rational explanation is
> that register information is postprocessed out in order to reduce
> information leakage.

Or that nVidia never wrote the driver in the first place. I cannot find any
nVidia copyrights on it -- it seems to have been reverse-engineered and then
written up by the current copyright holders.

> The shipped code is certainly not the preferred form for modification

TBH, I don't think there is any other form in existence, unless you want to
count the proprietary drivers this probably was reverse engineered from at
some distant past.

/* Steinar */
--
Homepage: http://www.sesse.net/


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