view doc/Loadtools-on-GTA0x @ 407:19e5a3e2f9c0

fcup-settime: moved time() retrieval a little closer to the output A fundamental problem with all simple time transfer tools is that there is always some delay between the time retrieval on the source system and that transmitted time being set on the destination, and the resulting time on the destination system is off by that delay amount. This delay cannot be fully eliminated when working in a simple environment like ours, but we should make our best effort to minimize it. In the present case, moving the atinterf_init() call before the time() retrieval should make a teensy-tiny improvement.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 11 Aug 2018 21:52:17 +0000
parents 1a658ab756fe
children
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FreeCalypso loadtools are currently a part of FC host tools, but they used to
be a separate package.  In those days that separate package of loadtools could
be built in two ways:

1) One could compile and install loadtools on a general-purpose host system
   such as a GNU/Linux PC or laptop, and then potentially use them to operate
   on multiple Calypso targets of different kinds.

2) One could compile loadtools to run on the application processor of a
   smartphone such as Openmoko GTA0x, in which case it makes no sense for that
   special build of loadtools to support any target other than the specific
   modem in that smartphone.

Loadtools can be built with compalstage support excluded and with
GTA0x-specific modem power control included instead.  This build will still
include a bunch of functions of no relevance to GTA0x, but oh well..

To build loadtools for the GTA0x AP, you'll need to make the following
modifications to loadtools/Makefile:

* Change the CC= line to point to the appropriate cross-compiler (which you'll
  need to provide yourself).

* Change the CFLAGS= line: add the right options to target the ARM920T core in
  the GTA0x AP (e.g., -march=armv4t -mtune=arm920t), and add -DGTA0x_AP_BUILD
  to enable some code that makes sense only when running on the GTA0x AP.

* Change the PROGS= line to not build fc-compalram or fc-buzplay: the latter
  utilities are not applicable to GTA0x.

* Change EXTRA_OBJ= from listing compalload.o to listing compaldummy.o and
  gtapower.o instead.

See loadtools/gta-ap-build.sed for an example.