Re: [9fans] Raspberry Pi 2 Model B

[Joe Bowers <joe@mixpanel.com>]

[-- Attachment #1: Type: text/plain, Size: 1659 bytes --]

FANTASTIC! Thank you so much! That's so cool!

On Fri, Feb 6, 2015 at 10:13 AM, Richard Miller <9fans@hamnavoe.com> wrote:

> To return to the original subject ...
>
> /n/sources/contrib/miller/9pi2 is a Plan 9 kernel which runs on the
> Raspberry Pi 2 (one core only, so far).  I'll put updated source
> in contrib/miller/9/bcm later today.  mk CONF'='pi2 for the new
> model, CONF'='pi for the original model.
>
>         Plan 9 from Bell Labs
>         firmware: rev 1422642103
>         cpu0: 900MHz ARM Cortex-A7 r0p5
>         fp: 32 registers,  simd
>         fp: arm arch VFPv3+ with common VFP subarch v2; rev 5
>         eMMC external clock 250 Mhz
>         #u/usb/ep1.0: dwcotg: port 0X0 irq 9
>         992M memory: 200M kernel data, 792M user, 3762M swap
>         usb/hub... usb/ether...
>         etherusb smsc: b827eb4f2fbd
>         usb/kb... usb/kb... root is from (local, tcp)[local]: tcp
>
> Even with one core activated, the rpi2 is noticeably quicker than
> the rpi.  Decoding a 1600x1200 jpeg with 'jpg -t' (from ramfs)
> takes about 5.8s on rpi, 3.2s on rpi2.
>
> Note that the publicity says 900Mhz, but the firmware boots at
> 600Mhz, and relies on dynamic clock and voltage management in
> linux to adjust the speed.  To get a fixed 900Mhz speed, I put
> this in config.txt:
>
>         kernel=9pi2
>         gpu_mem=16
>         disable_overscan=1
>         arm_freq=900
>         force_turbo=1
>
> Disclaimer: if you put silly numbers in arm_freq, bad stuff
> might happen.  Supposedly the firmware detects this and sets
> an irreversible bit somewhere that voids your warranty.
>
>
>

[-- Attachment #2: Type: text/html, Size: 2133 bytes --]