Stock environment

Software overview (A780-E680)

• MontaVista "mobilinux" additions
• dynamic power management
• EZX arm subarchitecture
• low-level drivers for:
  • SPI/SSP
  • PCAP Audio (mono/stereo/headset/...)
  • Vibrator (/dev/vibrator)
  • USB host port attached to BP
  • USB device port (belcarra usbd, not gadget)
  • Transflash/SD/MMC
• THREE proprietary flash file systems
  • Intel VFM (hatcreek.o)
  • m-systems DiskOnChip (tffs.o)
  • third unknown
• A1200 and ROKR E2 have custom Selinux static kernel module called motoac

The modified Linux kernel used on the Motorola Linux phones has been released by Motorola on SourceForge:

• http://sourceforge.net/projects/a760/
• http://sourceforge.net/projects/e680/

Multiple versions are available:

• linux_kernel_a760_2.tar.bz2 seems to be based on Linux 2.4.18, and was uploaded to SourceForge on 2004-08-09.
  • Judging from drivers/misc/ezx-log.c it seems to contain code for the A760 only.
• original_kernel.tar.gz seems to be based on Linux 2.4.20, and was uploaded to SourceForge on 2005-07-01.
  • Judging from drivers/misc/ezx-log.c it seems to contain code for the A760, E680, and A780
• original_kernel_2.tar.gz seems to be based on Linux 2.4.20, and was uploaded to SourceForge on 2006-01-06.
  • Judging from drivers/misc/ezx-log.c it seems to contain code for the A760, E680, and A780.

The Linux Kernel running on (most) EZX smartphones is a 2.4.20 based kernel, with the following modifications:

• Lots of hardware (cpu/architecture) related patches to mips/ppc/arm from MontaVista
• Drivers for
  • PXA270 Dynamic Power Management
  • PXA270 SD/MMC Controller (depending on firmware version statically linked !!)
  • Camera (v4l2 driver)
  • Keypad
  • Buttons
  • PXA270 Framebuffer
  • PXA270 Touchscreen
  • IPC (AP<->BP) USB Host
  • USB Device (Belcarra usbd, _not_ the Linux gadget driver)
• Proprietary kernel modules for
  • USB IPC demultiplex (mux_cli)
  • GPRS (gprsv)
  • Intel VFM (hatcreek) flash file system
    • Generic code is released by Intel upon request, but not GPL-compatible
  • MSystems TrueFFS (tffs) flash file system
    • Acts as a translation layer between VFAT and the underlying flash device
    • vfat is only required to achieve USB mass storage compatibility for Windows boxes
  • Logging/testing of AP, BP and DSP (logger)

Modules

mux_cli.o

• hooks into special functions of USB host driver
• provides GSM TS07.10 (de)multiplex
• userspace has tty devices

gprsv.o

• implements GPRS line discipline for mux_cli ttys
• hooks into netfilter to intercept DNS packets ?!?
• provides gprs0 / grps1 network devices

ipsec.o

• proprietary ipsec stack (don't we already have two GPL licensed?)
• Copyright Certicom Corp

Libraries

• glibc

Bluetooth

• proprietary userspace program directly opens HCI

GPS

• no NMEA, no serial device emulation :(
• proprietary library via mux_cli kernel module

UI

• embeddedQt
• Motorola EZX toolkit
• Low-level devices (framebufffer, etc) accessable.

Bootloader

• EZX bootloader
• based on GPL licensed blob
• low-level initialization code (GPIO config, clock, ...)
• vendor specific USB device allows for:
  • transfer of executable code from USB host
  • execution of transferred executable
• serial console code is present in binary (but not used)
• PST/RSD firmware updates work by uploading a "ramloader"