# HG changeset patch # User Mychaela Falconia # Date 1584045993 0 # Node ID 814d3f24bed6dbf8a41b276de1e6599b664efd24 # Parent 9805020b683418e129ee53af0c4515590a9f197b frbl/README: minor updates diff -r 9805020b6834 -r 814d3f24bed6 frbl/README --- a/frbl/README Sat Mar 07 06:54:17 2020 +0000 +++ b/frbl/README Thu Mar 12 20:46:33 2020 +0000 @@ -19,7 +19,19 @@ for L1 and GPF. The test subdirectory is intended to contain our frbl1test and frbl2test -programs; only frbl2test has been written so far. +programs; only frbl2test has been written so far. frbl2test implements the +host downloader side of the protocol we call FRBL2 in the same way how FLUID +(the PC-side application) implements it, allowing tests at both 115200 and +230400 baud as explained below. You need to provide a FreeCalypso-style (not +TI-style) S-record image to be fed to the target bootloader; helloapp from +freecalypso-tools/target-utils works ideally for this purpose. Because this +boot path does not go through the Calypso boot ROM, you will need to manually +select helloapp-irda.srec or helloapp-modem.srec, matching the Calypso UART you +are going through. frbl1test will work the same way if I ever get around to +writing it. + +230400 baud bogosity +==================== Aside from implementing two different serial protocols, TI's FRBL as featured in their Calypso firmwares has one other major quirk: both FRBL1 and FRBL2 were @@ -39,5 +51,10 @@ was clearly never intended or officially supported - instead the officially supported way for Leonardo and Leonardo-based customer designs was to use fluid -oo mode, which works through the boot ROM just like fc-loadtool. -However, there is a possibility that Openmoko may have tried to turn this FRBL -bug into a feature - we are still investigating. + +There is, however, an inexplicable mystery in that Openmoko seem to have used +fluid -oO mode somehow (at least with their version of FLUID that may have +unknown changes relative to TI's original) even though it should have never +worked at all. See this FreeCalypso community mailing list thread: + +https://www.freecalypso.org/pipermail/community/2020-March/000743.html