27 Nov
2011
27 Nov
'11
8:13 a.m.
Hi Marcin and Martin,
On Sun, Nov 27, 2011 at 01:17:37AM +0100, Marcin Mielczarczyk wrote:
ACK.
On the other
hand, I have access to very cheap phones using Infineon
PMB7880 (C166 + DSP) or MTK (ARM9) chipsets.
Note, that on the market there is much more Mediatek phones based on ARM7
(MT622x) than on ARM9 (MT623x). My Linux port for this architecture didn't touch
L1 at all. I focused first
on getting "application" cpu up and running.
I managed to configure TX path to transfer data on given frequency and
after that I had to have DSP running to send "proper" data.
All of this, once again, quite amazing work you've been pulling off. I
really regret that nobody (including myself) has ever since picked up on
it :(
I got stack on DSP part, because I tried first to
download firmware from
DSP ROM. This didn't work out so far.
Better approach would be to disassemble and understand DSP-ARM API and use
it as it is, without firmware changing for now.
Indeed, I agree, the best approach (like we took on Calypso) is to try
to use the DSP ROM code as-is. This reduces the required work to:
1) understand how to bring up (boot/start) the DSP from the ARM
2) understand how to drive the API from the ARM and feed instructions
into the DSP as well as read results
3) writing the required scheduler around those instruction/result
primitives, possibly porting/re-using some of the calypso L1 scheduler
Unfortunately I couldn't find time to work on that
due to my professional
work.
We can all understand that, but it's a real pity...
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
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