Roadrunner technical documentation

Write on QuadSPI memory with SAM-BA

Microchip SAM-BA is a software that provides an open set of tools for in-system programming of internal and external memories connected to Microchip 32-MCUs and MPUs. This article illustrates how to use it to transfer the at91bootstrap bootloader on the QuadSPI memory mounted on the RoadRunner SOM

In this article is used the command line version of SAM-BA version 3.3.1 that support the latest generations of Microchip MPUs.

The official version of SAM-BA is compatible with the QuadSPI memory used on the RoadRunner module up to the 16MB size (ROADRUNNER-Q16). To manage the higher memory size models follow this article:

Installing SAM-BA

Download the package from Microchip site:

mkdir roadrunner

Uncompress the tar.gz file:

tar xvf sam-ba_3.3.1-linux_x86_64.tar.gz

Move inside the new directory created by tar

cd sam-ba_3.3.1

Using SAM-BA

SAM-BA comunicates with MCU via the USB client port of Roadrunner. It can be used only when on the MPU is running RomBOOT. When the CPU is running Linux it is impossible to use SAM-BA to access the QuadSPI memory.

RomBOOT is the first piece of code that runs on the SAMA5D27 MCU at startup. It is burned directly by the Microchip factory inside the ROM MPU.

At startup RomBOOT looks for a bootable code from any possible supported external memory, if nothing is available, it waits for any serial commands incoming from the USB device port or from the serial debug port. This is the way used by SAM-BA to talk with RomBOOT.

If one the QuadSPI memory already contains boot code, it is possible to avoid to boot from it and remain on RomBOOT code closing the BOOT jumper on Berta board before the MPU reset.

The RoadRunner with QuadSPI on board (Model Q16/Q64/Q128) are already programmed to boot from QuadSPI. The default code put on it is at91bootstrap.

In case you want to reflash it just press the push-button BOOTOFF on the Berta D2 board and then press and release after one second the RESET button to restart the MPU. Then release the BOOTOFF pushbutton.

In this situation the RoadRunner MPU is inhibited to boot from the QuadSPI, it remains in RomBoot mode and a new USB device is announced on the USB port of your PC:

Bus 002 Device 004: ID <b>03eb:6124 Atmel Corp. at91sam SAMBA bootloader</b>

and a new serial device is available with the name /dev/ttyACM0:

[ 4676.045662] cdc_acm 2-2.1:1.0: ttyACM0: USB ACM device
[ 4676.046800] usbcore: registered new interface driver cdc_acm
[ 4676.046803] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

ls -al /dev/ttyACM0
crw-rw---- 1 root dialout 166, 0 Aug  2 12:53 /dev/ttyACM0

Examples to use SAM-BA from command line

Erase the whole QuadSPI

sudo ./sam-ba -p usb -b sama5d2-xplained -a qspiflash -c erase

Write the bootloader

sudo ./sam-ba -p usb -b sama5d2-xplained -a qspiflash -c writeboot:at91bootstrap.bin

Write to memory from a file

-c write:<filename>:[<addr>]

Examples: write and verify at91bootstrap.bin at begin of QuadSPI

sudo ./sam-ba -p usb -b sama5d2-xplained -a qspiflash -c write:at91bootstrap.bin   
sudo ./sam-ba -p usb -b sama5d2-xplained -a qspiflash -c verify:at91bootstrap.bin

Read memory to file

-c read:<filename>:[<addr>]:[<length>]


-c read:firmware.bin              read all to firmware.bin
-c read:firmware.bin:0x1000       read from 0x1000 to end into firmware.bin
-c read:firmware.bin:0x1000:1024  read 1024 bytes from 0x1000 into firmware.bin
-c read:firmware.bin::1024        read 1024 bytes from start of memory into firmware.bin

Verify memory from a file

-c verify:<filename>:[<addr>]


verify:firmware.bin         verify that start of memory matches firmware.bin
verify:firmware.bin:0x1000  verify that memory at offset 0x1000 matches firmware.bin

To generate different size sample files use these examples:

dd bs=1K count=64  < /dev/urandom > test64KB.bin
dd bs=1M count=16  < /dev/urandom > test16MB.bin
dd bs=1M count=64  < /dev/urandom > test64MB.bin
dd bs=1M count=128 < /dev/urandom > test128MB.bin

Using SAM-BA with QML script files

SAM-BA can execute scripts written in QML to do automaticaly complex functions.

With the following QML script for example it is possible to write and verify at91bootloader on the QuasSPI.

import SAMBA 3.2
import SAMBA.Connection.Serial 3.2
import SAMBA.Device.SAMA5D2 3.2

SerialConnection {
    port: "ttyACM0"
    baudRate: 115200

    device: SAMA5D2 {

    // read and display current BSCR/BUREG/FUSE values
    function printBootConfig() {
        var bscr = applet.readBootCfg(BootCfg.BSCR)
        print("BSCR=" + Utils.hex(bscr, 8) + " / " + BSCR.toText(bscr))
        var bureg0 = applet.readBootCfg(BootCfg.BUREG0)
        print("BUREG0=" + Utils.hex(bureg0, 8) + " / " + BCW.toText(bureg0))
        var bureg1 = applet.readBootCfg(BootCfg.BUREG1)
        print("BUREG1=" + Utils.hex(bureg1, 8) + " / " + BCW.toText(bureg1))
        var bureg2 = applet.readBootCfg(BootCfg.BUREG2)
        print("BUREG2=" + Utils.hex(bureg2, 8) + " / " + BCW.toText(bureg2))
        var bureg3 = applet.readBootCfg(BootCfg.BUREG3)
        print("BUREG3=" + Utils.hex(bureg3, 8) + " / " + BCW.toText(bureg3))
        var fuse = applet.readBootCfg(BootCfg.FUSE)
        print("FUSE=" + Utils.hex(fuse, 8) + " / " + BCW.toText(fuse))

    onConnectionOpened: {
        // initialize QSPI applet

        // erase all memory
        applet.erase(0, applet.memorySize)

        // write files
        applet.write(0x00000, "at91bootstrap.bin", true)

        // verify files
        applet.verify(0x00000, "at91bootstrap.bin", true)

        // initialize boot config applet

        // Use BUREG0 as boot configuration word
        applet.writeBootCfg(BootCfg.BSCR, BSCR.fromText("VALID,BUREG0"))

        // Write flags in RAM
        applet.writeBootCfg(BootCfg.BUREG0, BCW.fromText("EXT_MEM_BOOT,QSPI0_IOSET3"))

        // Write flags on FUSES
        //applet.writeBootCfg(BootCfg.FUSE, BCW.fromText("EXT_MEM_BOOT,QSPI0_IOSET3"))


save it in a file called for example mytest.qml then lauch it by typing:

sudo ./sam-ba -x mytest.qml

More info about SAM-BA is availabe in doc/index.html to read it type inside the SAM-BA directory:

cd doc
python -m SimpleHTTPServer 8000 

then access to this url http://localhost:8000 from your web browser.

Time required for QuadSPI operation

Memory size in MB Write all (mm:ss) Verify all (mm:ss)
16 2:12 2:25
64 8:50 0:11
128 17:38 0:19


Sergio Tanzilli
Systems designer, webmaster of and founder of Acme Systems srl

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Roadrunner technical documentation