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This builds a USB DFU compatible boot loader for sam3u based boards.
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2
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3
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try
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4
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make BOARD=at91sam3u-ek
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5
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or
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6
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make BOARD=osmo-sdr
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7
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depending on your board type.
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8
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9
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The result is a < 16kBytes file in the ./bin/ subdirectory, which you can
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10
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flash using JTAG, SAM-BA or rum-ba to the beginning of FLASH0.
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11
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12
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The DFU loader will check in early boot if the "DFU button" is set. If yes,
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13
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it will enter the DFU mode, if not it continuest to boot directly the
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14
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application.
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15
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16
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DFU button mappings:
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17
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at91sam3u-ek: Button marked PB-LEFT on the board
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18
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osmo-sdr: PA12 (can be closed with a jumper on the header)
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19
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20
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The regular application program can change from run-time to DFU mode quite
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21
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easily. In fact, this happens using a standardized USB control request and is
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22
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thus already implemented in the at91lib.git on git.gnumonks.org.
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23
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24
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You can switch the device from runtime into DFU mode using
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25
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dfu-util -e -d 0x16c0:0x0763
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26
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27
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After that, you can flash a new application image into the respective partition using
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28
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dfu-util -d 0x16c0:0x0763 -a0 -D ./bin/my-foobar-project-dfu.bin
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29
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30
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which should show something like:
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31
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Opening DFU capable USB device... ID 16c0:0763
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Run-time device DFU version 0100
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34
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Found DFU: [16c0:0763] devnum=0, cfg=1, intf=0, alt=0, name="OsmoSDR DFU Interface - Application Partition"
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35
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[...]
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36
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Starting download: [##################################################] finished!
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state(7) = dfuMANIFEST, status(0) = No error condition is present
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38
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state(2) = dfuIDLE, status(0) = No error condition is present
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39
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40
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41
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However, that application has to be built using a compatible linker script.
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42
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43
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building application firmware for DFU
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44
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=====================================
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45
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46
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This needs a special linker script which is implemented as dfu.lds in the
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47
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at91lib repository on git.gnumonks.org. You can then build your project to
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48
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get linked to the "application partition" using
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49
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make dfu
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50
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in the respective project directory
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51
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52
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There is a 'usb-fast-audi-source' project that can be used for demonstration
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53
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purpose, it has 'make BOARD=osmo-sdr dfu' support
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54
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