On Wednesday 11 February 2015 21:43:42 Pavel Machek wrote: > Hi! > > On Sun 2015-02-01 09:56:28, Pali Rohár wrote: > > On Sunday 01 February 2015 02:36:06 Matthijs van Duin wrote: > > > On 31 January 2015 at 20:06, Pali Rohár > > > <pali.rohar@xxxxxxxxx> > > > > > > wrote: > > > > I have configured two testing N900 devices. One with > > > > signed bootloader which enable omap aes support and one > > > > device with signed bootloader which does not enable > > > > omap aes support. > > > > > > I'm probably missing some context here, but why not just > > > use the one with aes support? Alternatively, one may > > > argue that it's the bootloader's job to provide the > > > kernel with an accurate device tree. (Though one may > > > equally well argue that it would be nice to avoid having > > > to customize the device tree for every feature-flavor of > > > a processor, especially if this depends on how it's > > > initialized.) > > > > Nokia X-Loader is closed source and signed. So we cannot > > modify it. And it is responsible for configuring L3/L4 > > firewall. > > > > Year ago it was possible to find on internet signed X-Loader > > for N900 which enable omap aes support (for testing purpose > > together with open source linux kernel modules), but it is > > unofficial and I think there only too few people who > > flashed it into N900 nand. If somebody needs binaries I > > have backup all of them. > > > > More info about that aes enabled X-Loader: > > http://maemo.org/community/maemo-developers/n900_aes_and_sha > > 1-md5_hw_acceleration_drivers/ > > > > Majority of users use only official X-Loader which does not > > enable aes support so we cannot enable kernel modules (cause > > crashes). And also we cannot force users to flash some > > unofficial binary into their device... > > BTW... it would be interesting to know... are you doing some > heavy crypto processing on N900? Are the accelerated drivers > faster than non-accelerated ones? Because the link above says > they are slower... > > # Eric Wheeler > # ... > # Hey guys, I have omap-aes compiled for my kernel and appears > to be # working. > # > # I do not understand why non-accelerated software-crypto is > faster than # the omap-aes hardware acceleration: > # > # mmcblk0 onboard 32GB: read=21.76MB/s write=12.97MB/s > # aes_generic crypto: read= 8.47 write= 5.54 > # omap-aes hw crypto: read= 6.31 write= 5.45 > # > # mmcblk1 uSD 16GB Class 10: read=16.05MB/s write=16.47MB/s > # aes_generic crypto: read= 7.96 write= 7.43 > # omap-aes hw crypto: read= 6.67 write= 7.18 > > Best regards, > Pavel Also depends on CPU usage. Same as there was preview of theora decoder. One neon optimized running at arm core provided better fps, but used 99%. Another implementation which used DSP core provided lower fps, but enough for watching videos and did not used full CPU usage... -- Pali Rohár pali.rohar@xxxxxxxxx
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