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view doc/Loadtools-on-GTA0x @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Mon, 11 Feb 2019 00:00:19 +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.