mirror of https://github.com/EttusResearch/uhd.git synced 2026-10-25 17:36:10 +00:00

Martin Anderseck 155dfbf352 fx3: Upgrade B2xx build

This is an upgrade to the latest FX3 SDK (1.3.5) and to the ARM gcc in
version 15.3.rel1 for the build of the B2xx firmware and bootloader. All
required steps are explained in the updated readme file.
Additionally, some bounds checks were added both in the firmware and the
bootloader, as well as some more validations and checks to prevent over-
and underflows. Newly introduced checks were documented in the code.

2026-09-30 11:54:00 +02:00

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INSTRUCTIONS

Building the B2xx FX3 Firmware

The USRP B200 and B210 each use the Cypress FX3 USB3 PHY for USB3 connectivity. This device has an ARM core on it, which is programmed in C. This README will show you how to build our firmware and bootloader source.

A brief "Theory of Operations": The host sends commands to the FX3, our USB3 PHY, which has an on-board ARM which runs the FX3 firmware code (hex file). That code is responsible for managing the transport from the host to the FPGA by configuring IO and DMA.

Setting up the Cypress SDK

In order to compile the USRP B200 and B210 bootloader and firmware, you will need the FX3 SDK distributed by Cypress Semiconductor. You can download the FX3 SDK from here. Version 1.3.5 is known to be working.

From the SDK, extract the ARM cross-compile toolchain tarball ARM-GCC.tar.gz and the FX3 firmware tarball fx3_firmware_linux.tar.gz. Get the latest version of the GNU Toolchains for ARM from arm.com and extract it. Version 15.3.rel1 is known to be working.

Set up the appropriate environment variables for the build:

    $ export ARMGCC_INSTALL_PATH=<ARM toolchain dir>
    $ export ARMGCC_VERSION=<ARM toolchain version>
    $ export FX3FWROOT=<FX3 firmware dir>

These should look something like this:

    $ export ARMGCC_INSTALL_PATH=/path/to/my/files/arm-gnu-toolchain-15.3.rel1-x86_64-arm-none-eabi
    $ export ARMGCC_VERSION=15.3.1
    $ export FX3FWROOT=/path/to/my/files/cyfx3sdk

The SDK makefiles invoke arm-none-eabi-gcc unqualified and only use ARMGCC_INSTALL_PATH to locate the libraries, so the toolchain must also be on your PATH:

    $ export PATH=$ARMGCC_INSTALL_PATH/bin:$PATH

Without this, the build either fails with arm-none-eabi-gcc: No such file or directory or, if a different ARM toolchain happens to be installed, silently compiles with that compiler while linking against the libraries of the toolchain above. Verify the expected compiler is picked up:

    $ arm-none-eabi-gcc --version

Applying the Patch to the Toolchain

Now, you'll need to apply a patch to some files in the Cypress SDK. Before doing so, ensure all files in the SDK have Unix line endings and are writable for the user:

    $ cd $FX3FWROOT
    $ find . -type f -exec dos2unix {} \; -exec chmod u+w {} \;

Apply the patch b200/fx3_mem_map.patch as follows:

    $ cd uhd.git/firmware/fx3
    $ patch -p1 -d $FX3FWROOT < b200/fx3_mem_map.patch

If you don't see any errors print on the screen, then the patch was successful.

Building the Firmware

Now, you should be able to head into the b200/firmware directory and simply build the firmware:

    $ cd uhd.git/firmware/fx3/b200/firmware
    $ make

It will generate a usrp_b200_fw.hex file, which you can then give to UHD to program your USRP B200 or USRP B210.

Building the Bootloader

The bootloader is built in the b200/bootloader directory:

    $ cd uhd.git/firmware/fx3/b200/bootloader
    $ make

It will generate a usrp_b200_bl.img file, which you can supply as an argument to b2xx_fx3_utils to load it onto the device.

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