So I added the register calling conventions for the architectures that scripts/mcm-buildall.sh builds toolchains for (I.E. the ones I'm testing under qemu with scripts/mkroot.sh), but when I tried to build strace for the sh4 target it went "boing" a lot because the available syscalls don't entirely match up between architectures.
Sigh. I knew this was coming. That's why it was still on my todo list. I've been looking at the kernel syscall plumbing anyway due to http://lkml.iu.edu/hypermail/linux/kernel/2111.3/00074.html and it turns out the toolchain has a full manifest of available syscalls in /usr/include/asm-generic/unistd.h (which seems an odd place for it, but sure, why not). That header is installed in each toolchain, so we can just reach out and grab it at build time. That information maps the system call number to the system call function name, but where do we get the function prototypes for each system call? Answer: they're in include/linux/syscalls.h in the kernel source, but THAT file is architecture indepdendent so we only need one copy for all architectures. The following Horrible Sed Invocation rips them out, cleans them up, and sorts them with duplicates eliminated: sed -E '/^asmlinkage long sys_/!d;:l;/;/b e;N;b l;:e;s/\n/ /g;s/[ \t][ \t]*(__user|)[ \t*]/ /g;p' include/linux/syscalls.h | sort -u (The result is almost certainly scenes a faire, I.E. there is no creativity in this data arrangement, and thus the result is not copyrightable. Modulo the stupid oratroll "API copyright" nonsense, which we'd already be screwed by including any part of /usr/include/linux if that was true. But you can fish 95% of the same info out of https://man7.org/linux/man-pages/man2/syscalls.2.html if you follow the links.) The NEXT question is where we get the structure definitions, with all types squashed to primitive types, for conversion into the "banana|{potato}" strings the plumbing is trying to parse. Unfortunately THIS part may vary by architecture again; the file #includes a bunch of things and is an #ifdef salad. Still working on that... Rob _______________________________________________ Toybox mailing list Toybox@lists.landley.net http://lists.landley.net/listinfo.cgi/toybox-landley.net
