Firmware » History » Revision 2
Revision 1 (laforge, 02/19/2016 10:50 PM) → Revision 2/8 (laforge, 02/19/2016 10:50 PM)
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= OsmoSDR Firmware =
The OsmoSDR firmware is written in C language. It uses a modified version of the Atmel-provided sam3u drivers (at91lib).
There are multiple firmware images available, providing different interfaces towards the host PC.
== Firmware Variants ==
There are multiple firmware images available, providing different interfaces towards the host PC.
=== standard (usb-audio) firmware ===
The standard firmware image exports a composite USB device with two interfaces:
* A USB standard audio class device (for actual received baseband samples)
* A USB CDC-ACM serial device (for hardware control like tuning)
The audio class device offers (at least) two sample rates:
* a high sample rate (1/2/4 MHz) for USB Audio drivers like the ALSA driver included in mainline Linux
* a low sample rate of 96 kHz (possibly 128 kHz) to work with the poor USB Audio driver of MS Windows OSs
== Firmware flashing ==
There are two methods of flashing the firmware:
=== DFU firmware flashing ===
This is currently being worked on. FIXME.
=== SAM-BA / rum-ba firmware flashing ===
The sam3u contains a ROM based recovery boot loader called "SAM-BA". To activate this loader,
you have to
* power down the device
* close the ERASE jumper
* power up the device (1 second is sufficient)
* power down the device
* remove the ERASE jumper
* power up the device again
You will now the SAM-BA enumerate on USB using the following parameters:
* Vendor ID 0x03eb
* Product ID 0x6124
* String: "Atmel Corp. at91sam SAMBA bootloader"
The SAM-BA loader exports a CDC-ACM (virtual serial port) interface.
You can now use either Atmel's original host PC software (large, complex) or the {{{rum-ba}}} program provided by OsmoSDR to flash the full firmware image:
{{{
$ ./rumba /dev/ttyACM0 flash firmware_file_name.samba
}}}
== Firmware building ==
You first need to build and/or obtain a Cortex-M3 [wiki:Toolchain].
