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doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 25 Mar 2018 07:07:49 +0000
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children 15c61c8f3166
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474
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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1 Our current FCDEV3B boards exhibit a hardware bug: the reset input to the flash
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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2 chip is connected to Calypso's FDP output per both TI's Leonardo reference
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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3 schematics and Openmoko's working design, but this arrangement turns out to be
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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4 unsuitable for the high-capacity Spansion S71PL129NC0HFW4B flash+pSRAM chip we
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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5 are using, copied from Pirelli DP-L10. This hardware bug has manifested itself
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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6 in two different ways so far:
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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7
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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8 * Out of the 20 boards we've built so far, on just one board there was an issue
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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9 where our standard Magnetite fw would have trouble booting from flash, but
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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10 RAM-loaded fw booted fine. Interrupting the boot process serially and having
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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11 the serially loaded code jump to the image in flash also worked fine.
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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12 Eventually it was found that the flash boot problem on that one board occurs
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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13 only when flash boot mode 1 is used, whereas flash boot mode 0 works fine. I
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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14 (Mychaela) suspect that the problem has something to do with the watchdog
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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15 reset that happens as part of flash boot mode 1, the FDP output behaviour
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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16 during that watchdog reset, and the flash chip's reaction to the latter.
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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18 * On all of the boards there is a problem with sleep modes: when the firmware
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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19 is running from flash as opposed to RAM, certain sleep-wake sequences cause
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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20 an erratic self-reboot or a hang. It is suspected (though not proven yet)
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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21 that the FDP output goes low during all sleep modes, our Spansion flash chip
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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22 gets unhappy with the reset timing it gets subjected to, and some flash reads
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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23 (instruction fetches) don't work after wakeup. So far the only workable
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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24 solution has been to disable all sleep modes in all FCDEV3B fw builds;
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
parents:
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25 nothing else has been successful.
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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26
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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27 The fcdev3b-hacks directory contains two hacks that can be applied to FCDEV3B
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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28 firmware images (fwimage.bin builds) as xxd binary patches:
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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29
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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30 * The first hack dating from 2017-05 patches the fw to use flash boot mode 0
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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31 instead of TI's original flash boot mode 1, but after boot the FFFF:FB10
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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32 register is set to put the flash and not the internal ROM at address 0, so
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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33 the interrupt and exception vectors go to the flash like in TI's original fw,
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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34 not through the internal ROM. This hack was put together for the purpose of
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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35 producing flashable fw images that boot without problems on that one board on
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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36 which flash boot mode 1 didn't work, and worked successfully for that purpose.
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
parents:
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37
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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38 * The second hack dating from 2018-03 patches the fw to not only use flash boot
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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39 mode 0, but also route the interrupt and exception vectors through Calypso's
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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40 internal ROM. I was hoping that this hack would make the sleep mode problem
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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41 go away by having the Calypso execute some cycles out of its internal ROM and
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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42 RAM before hitting the flash after wakeup, but nope, bringing up the SIM
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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43 interface with AT+CFUN=1 in the l1reconst config when running from flash with
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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44 small sleep enabled still triggers erratic misbehaviour even with this patch.
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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45
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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46 The proper fix will be to change the PCB to not connect the flash chip's reset
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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47 input to FDP any more, and connect it to a pull-up resistor instead. But this
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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48 fix will require an expensive PCB respin, hence some experiments to test this
8fbf3c0ea8b6 doc: Flash-boot-mode-hack article replaced with FCDEV3B-hardware-bug
Mychaela Falconia <falcon@freecalypso.org>
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49 idea will need to be done first.