FreeCalypso > hg > freecalypso-tools
view doc/Flash-boot-wa @ 1014:961efadd530a default tip
fc-shell TCH DL handler: add support for CSD modes
TCH DL capture mechanism in FC Tourmaline firmware has been extended
to support CSD modes in addition to speech - add the necessary support
on the host tools side.
It needs to be noted that this mechanism in its present state does NOT
provide the debug utility value that was sought: as we learned only
after the code was implemented, TI's DSP has a misfeature in that the
buffer we are reading (a_dd_0[]) is zeroed out when the IDS block
is enabled, i.e., we are reading all zeros and not the real DL bits
we were after. But since the code has already been written, we are
keeping it - perhaps we can do some tests with IDS disabled.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Tue, 26 Nov 2024 06:27:43 +0000 |
| parents | efb93f3e4ac7 |
| children |
line wrap: on
line source
There is a tiny (120 bytes SREC file) program called flash-boot-wa that was written in the spring of 2017 for the purpose of working around a problem that happened on only one first-batch FCDEV3B board and never happened on any other board - but Murphy's law had it that this one troubled board just had to be the one on which my (Mother Mychaela's) very initial development and bring-up work was done. The defect exhibited on that one board was as follows: it had no problem booting serially (fc-iram, fc-loadtool, fc-xram) and it had no problem booting from flash in mode 0 (see the Flash-boot-modes article in the freecalypso-docs repository), but booting from flash in mode 1 (the flash boot mode used by FC Magnetite, which is our primary firmware) was troubled. The exact failure mode and the root cause were never solved, but the issue most likely involved the watchdog reset in some way (it occurs as part of flash boot mode 1 but not in mode 0 and not in serial downloading), and because Calypso's FDP output goes low during watchdog reset (or at least TI's CAL000 document says so), it is plausible that the root cause involved the Spansion flash chip getting unhappy as a result of being jerked with extra resets which don't meet its reset timing requirements. Our new FCDEV3B V2 boards no longer use Calypso's FDP output (it is left unconnected) and feature a new flash reset circuit of our own design that meets the reset timing requirements of our Spansion flash chip, hence the flash boot problem seen on that one FCDEV3B S/N 001 board is not expected to recur on any of our current or future boards. However, our little flash-boot-wa program is kept around: removing a previously-released 120-byte program for no good reason is not the way of FOSS. This flash-boot-wa program is loaded serially via fc-iram; it disables the boot ROM and jumps to address 0 (the opposite of what we do in compalstage for Mot C1xx phones), thereby indirectly booting the made-for-boot-mode-1 firmware image in the flash. The intended usage was as follows: fc-iram -h fcfam /dev/ttyXXX /opt/freecalypso/target-bin/flash-boot-wa.srec rvinterf It is also worth noting that fc-iram has been extended to support second program invokation just like fc-xram (used in the invokation line above) just for this peculiar use case. The flash-boot-wa.srec helper can also be booted via fc-xram.