view doc/FCDEV3B-751774 @ 662:8cd8fd15a095

SIM speed enhancement re-enabled and made configurable TI's original code supported SIM speed enhancement, but Openmoko had it disabled, and OM's disabling of speed enhancement somehow caused certain SIM cards to start working which didn't work before (OM's bug #666). Because our FC community is much smaller in year 2020 than OM's community was in their day, we are not able to find one of those #666-affected SIMs, thus the real issue they had encountered remains elusive. Thus our solution is to re-enable SIM speed enhancement and simply wait for if and when someone runs into a #666-affected SIM once again. We provide a SIM_allow_speed_enhancement global variable that allows SIM speed enhancement to be enabled or disabled per session, and an /etc/SIM_spenh file in FFS that allows it to enabled or disabled on a non-volatile basis. SIM speed enhancement is now enabled by default.
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 24 May 2020 05:02:28 +0000
parents 9f19cc5e46e8
children
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We have one experimental FCDEV3B V2 board on which our regular Calypso chip
([P]D751992AGHH) has been replaced with D751774AGHH, an earlier F-number
featuring DSP ROM version 3416 rather than the final version 3606 which we
normally work with.  Both chip versions are Calypso C035 variants (ARM7 running
at 52 MHz, DSP running at 104 MHz), and both include AMR support - but there
must have been some issue with DSP version 34 (and maybe version 35 used in
Calypso+) that compelled TI to produce the newer and final version 36 which we
are most familiar with.

Our Layer1 code is based on TI's TCS211-20070608 semi-src release (which we have
reconstructed back to full source), and it officially supports only DSP 36.
However, our FC Magnetite firmware can also be built for DSP 34 targets (see
the Calypso-version-override article), in which case we use a monolithic DSP
patch (no L1_DYN_DSP_DWNLD) extracted from the TSM30 source.  The patch version
is 4130.

The configure.sh target name for this special modified board is fcdev3b-dsp34
instead of just fcdev3b, and the two firmware builds are not interchangeable:
the regular fcdev3b build goes into regular FCDEV3B boards, the special
fcdev3b-dsp34 build goes into the special FCDEV3B-751774 board.  However, when
running its respective build this DSP 34 board appears to function just as well
as our regular DSP 36 targets: standalone RF tests work, DSP-based audio
services (beeps and Melody E1) work, connecting to a live GSM network worked,
a few test voice calls worked, all of them connected in AMR mode, voice passed
successfully in both directions.

Going forward, we shall continue using D751992AGHH chips with DSP ROM version
3606 as our regular platform, but it is nice to know that the earlier DSP 34
apparently works too.