Areas of Work¶

This page lists the various areas of the project that require some work, and who (if at all) is
working on fixing it.

Infrastructure¶

Build System¶

• we need a clean/known base as a compiler
  • At the moment, we're mostly using the 4.0.2 release from gnuarm.com, which is fairly old
• independence of system-provided header files
  • We should be mostly there now. But testing this and verifying our independence of system headers would be great

Operating System¶

• Decide which RTOS to use on the Calypso
  • we don't want to use FreeRTOS because...
  • OS should have clear abstraction of core (ARM7TDM), SoC and board level features
  • OS should cleanly compile to a library that we can link with all our other code
  • While we only work on the GSM stack, no OS is needed. But as soon as UI comes around, that changes.
  • Some of the potential choices could be
    • uKOS-II http://www.ukos.ch/
    • Erika OSEK/VDX http://erika.tuxfamily.org/wiki/index.php?title=Main_Page
    • ChibiOS/Nil http://www.chibios.org/dokuwiki/doku.php

Development Tools¶

• try to make JTAG (C155) work with OpenOCD
  • steve-m made some experiments, but halting the ARM core only seems to be possible via the undocumented ICEPick unit
  • works now, required sniffing the TI CCS debugger, see here.

Host Software¶

• osmocon support for the native ROM loader in the Calypso, the HardwareCalypsoRomloader, like it is found on most non-Compal phones
  • "non-secure" variant (done, steve-m)
  • "secure variant" on Calypso/Calypso plus (basic reverse engineering done)

Target Software¶

Drivers¶

• (DONE) Fix the I2C driver to use the b/w LCD without any sleep/delay loops (sigwinch)
• (DONE) charger detection, battery charging (roh)
• (DONE) SIM card reader (dexter)
• (DONE) Color display driver for C155 (steve-m)
• (DONE) buzzer driver for C123
• (DONE) backlight driver
• C155 ringtone chip driver for SPMA100 chip
• vibrator driver

GSM Stuff¶

• TRF6151, TPU, TSP, AGC, AFC (laforge)
• Layer1, particularly the synchronous part (laforge, spaar)
• Layer2 (zecke, laforge)
• Layer3 (eversberg)
• Playing with the Voice part using the dsp misc task (spaar?)

General Infrastructure¶

• Flash-based log-structured filesystem (prom)

Bootloader¶

• Put together a bootloader (prom)
• Define linkage situations (prom)

UI related¶

• proportional fonts in at least two sizes, as small as possible
  • monospaced fonts waste too much scarce screen real estate
• cache the frame buffer in RAM and sync when needed
  • once we have a scheduler and tasks, run screen refresh as low-priority task
• hardware independent API to support C123, C155 (and later other) displays
  • software should not care if it is using color or b/w display
• some kind of fixed screen layout masks, where
  • a data structure defines a screen mask
  • the application can easily update the content without having to deal with formatting/positioning
• UI widgets like
  • lists that can be scrolled through
  • menus build of a tree of such lists