Wiki > Main > SansaFuzePlusFirmware (compare)
Difference: SansaFuzePlusFirmware (r8 vs. r7)
This page will summarize important things about the Sans Fuze+ firmware. See SansaFuzePlus for more information about the device and SbFileFormat for more information about the format of the firmware.
All the content of this page specifically applies to the 1.30.01 firmware, although the majority of the information should apply to any firmware revision. This page uses a hierarchical structure: it is first divide in boot sections as extracted by the sbinfo tools. Then his section is divide in several subsection which correspond to the different elf files generated by the sbinfo tool.
An important side note is about the firmware.sb file. It is, indeed split into three sections. However, one can notice that each section ends with a "jump" (See SbFileFormat). This means suggest that there one is no apparent way of executable a section which the first boot section. Disassembly stages uses of the last features part of the boot section suggest that it call command to branch to loads something from the disk so perhaps other sections. The the "play" and "host" section of firmware.sb are written on the disk and later loaded by the boot code depending on the usb connection. This would explain why the last part of the boot section shares so much code with "play" and "host" like SSP, threading, interrupt, ... (this is the exact same code). This code might also be involved in firmware updates.
To summarize, the boot process of the fuze+ is rather unclear for now.
This section seems to be a kind of bootloader, in the sense that it does lots of initialization. In the code seems quite generic, having support for several kinds of drams, lcds, ...
This first elf file mainly contains power initializations routines, probably to find the best power source. It also setup things like battery monitoring, brownout paths, ...
This second elf file mainly contains dram initializations routines. It probably detects the kind of dram attached, setup clocks, EMI, ...
This third elf file also does some dram initialization, as well as enable various clocks for peripheral likes CPU, SSP, GPMI, ...
The content of this file has been partially examined.
The content of this file has been partially examined. It to deal with lcd, debug uart, ssp and peripheral (clocks, dram, emi, ...). It probably has to do with the actual loading of the fuze+ OF. It might also been involved in firmware updates.
This part of the firmware seems to handle the connection to the host, in either USB MSC or MTP mode.
This file displays the video/logo that one can see at boot time (the sansa logo exploding into a flower). It's mainly a 3Mb raw video with some LCD code to display it. The video itself has 10 frames.
This is the actual OF.
The Fuze+ firmware is based on the ThreadX? RTOS. As such, it implements the ThreadX? API. As far as I have checked, this document perfectly matches the code found in the firmware: ThreadX User Guide. The firmware also happen to be particularly complicated, involving lots of threading, DPC (deferred procedure code), lots of indirect layers and callbacks, which suggest that the code is a complete RTOS and has not been developed for the Fuze+.
-- AmauryPouly - 03 Dec 2010
r8 - 09 Jul 2011 - 00:33:33 - AmauryPoulyRevision r8 - 09 Jul 2011 - 00:33 - AmauryPouly
Revision r7 - 02 May 2011 - 22:50 - AmauryPouly
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