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fc-loadtool help: improve language regarding 16 MiB flash chips In FC project history, 16 MiB flash originally meant Pirelli DP-L10. Then we got FCDEV3B with the same flash (our own design), but now we are discovering more Calypso devices that used such large flash, both late Calypso era (Sony Ericsson K2x0) as well as much earlier ones (FIC FLUID devices.txt file with 2004 dates, Leonardo+ rev 5). Hence we need to migrate to more generic or neutral language in associated documentation, without giving elevated status to specific examples that drove our early project history.
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 03 Dec 2023 21:11:12 +0000
parents efb93f3e4ac7
children
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efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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1 There is a tiny (120 bytes SREC file) program called flash-boot-wa that was
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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2 written in the spring of 2017 for the purpose of working around a problem that
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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3 happened on only one first-batch FCDEV3B board and never happened on any other
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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4 board - but Murphy's law had it that this one troubled board just had to be the
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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5 one on which my (Mother Mychaela's) very initial development and bring-up work
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Mychaela Falconia <falcon@freecalypso.org>
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6 was done.
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Mychaela Falconia <falcon@freecalypso.org>
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7
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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8 The defect exhibited on that one board was as follows: it had no problem booting
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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9 serially (fc-iram, fc-loadtool, fc-xram) and it had no problem booting from
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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10 flash in mode 0 (see the Flash-boot-modes article in the freecalypso-docs
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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11 repository), but booting from flash in mode 1 (the flash boot mode used by
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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12 FC Magnetite, which is our primary firmware) was troubled. The exact failure
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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13 mode and the root cause were never solved, but the issue most likely involved
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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14 the watchdog reset in some way (it occurs as part of flash boot mode 1 but not
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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15 in mode 0 and not in serial downloading), and because Calypso's FDP output goes
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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16 low during watchdog reset (or at least TI's CAL000 document says so), it is
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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17 plausible that the root cause involved the Spansion flash chip getting unhappy
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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18 as a result of being jerked with extra resets which don't meet its reset timing
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Mychaela Falconia <falcon@freecalypso.org>
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19 requirements.
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Mychaela Falconia <falcon@freecalypso.org>
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20
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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21 Our new FCDEV3B V2 boards no longer use Calypso's FDP output (it is left
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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22 unconnected) and feature a new flash reset circuit of our own design that meets
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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23 the reset timing requirements of our Spansion flash chip, hence the flash boot
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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24 problem seen on that one FCDEV3B S/N 001 board is not expected to recur on any
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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25 of our current or future boards. However, our little flash-boot-wa program is
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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26 kept around: removing a previously-released 120-byte program for no good reason
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Mychaela Falconia <falcon@freecalypso.org>
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27 is not the way of FOSS.
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Mychaela Falconia <falcon@freecalypso.org>
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28
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Mychaela Falconia <falcon@freecalypso.org>
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29 This flash-boot-wa program is loaded serially via fc-iram; it disables the boot
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Mychaela Falconia <falcon@freecalypso.org>
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30 ROM and jumps to address 0 (the opposite of what we do in compalstage for Mot
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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31 C1xx phones), thereby indirectly booting the made-for-boot-mode-1 firmware image
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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32 in the flash. The intended usage was as follows:
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Mychaela Falconia <falcon@freecalypso.org>
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33
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Mychaela Falconia <falcon@freecalypso.org>
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34 fc-iram -h fcfam /dev/ttyXXX /opt/freecalypso/target-bin/flash-boot-wa.srec rvinterf
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Mychaela Falconia <falcon@freecalypso.org>
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35
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Mychaela Falconia <falcon@freecalypso.org>
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36 It is also worth noting that fc-iram has been extended to support second program
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Mychaela Falconia <falcon@freecalypso.org>
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37 invokation just like fc-xram (used in the invokation line above) just for this
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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38 peculiar use case. The flash-boot-wa.srec helper can also be booted via
efb93f3e4ac7 doc/Flash-boot-wa: explanatory article added
Mychaela Falconia <falcon@freecalypso.org>
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39 fc-xram.