On Thursday 12 June 2008 12:14:32 Bill Gatliff wrote: > Paul Mundt wrote: > > Yes, that's the easy case. It's things like perl that are the corner > > cases, and my objection comes from the fact that people think we ought to > > not have the kernel depend on perl rather than just fixing the package > > itself. Autoconf/libtool damage is an entirely different problem :-) > > At first glance, it seems like checkincludes.pl could be duplicated by > egrep | uniq | wc vs. egrep | wc. Not quite sure what checkversion.pl is > trying to do.
There's a difference between "this is a development tool used while modifying source code" and "this is needed to build". There are situations where it's ok to have a dependency on X11/qt/gtk, such as "make xconfig". This is _not_ the same as adding such dependency to "make modules". So far, none of the perl dependencies prevent you from building the kernel on a system that didn't have perl (or didn't have the right version of perl). > So maybe we could _reduce_ dependency on perl, if there's any advantage to > gain by doing so. But the kernel build machinery isn't dependent on very > many other systems (just tcl, bash and gcc-core), There's no tcl dependency in the build. (Yes, I actually know this.) Part of my FWL work involves getting the system to rebuild itself under itself. (The packages you need to make a minimal self-bootstrapping system are gcc, binutils, make, bash, uClibc, linux, and busybox/toybox). I'm seven commands away from doing this. I know this because I made a horrible little wrapper (attached, it really is sad) which touched a file with the name it was called as and then exec()ed the actual executable out of another directory. Then I populated a directory with symlinks to every executable in $PATH (for i in `echo $PATH | sed 's/:/ /g'`;do for j in `ls $i`; do ln -s $i/$j $j; done; done), and another directory of similar symlinks to my wrapper. I then ran my build with that wrapper directory at the start of $PATH and let the wrapper populate a directory with all the executables that actually got called during the build. Then I filled up a directory with those executables, tried to run the build, and figured out why it broke. (The above approach won't find calls to /bin/bash and a few other things, but it's a good start.) Most of the point of my ./host-tools.sh wrapper in the FWL build is to populate a directory with the command line utilities mini-native will have in it (specifically the busybox/toybox versions, not the ones in the host system), and set $PATH equal to that directory and only that directory. This way I know the system will build under itself because that's how it's building in the first place. Currently, I need to grab the following out of the host system: for i in ar as nm cc gcc make ld bzip2 find install od sort diff wget do [ ! -f "${HOSTTOOLS}/$i" ] && (ln -s `which $i` "${HOSTTOOLS}/$i" || dienow) done The first seven are the needed bits of the host toolchain (you'd think "strip" would be in there, but it turns out those packages only ever use $TARGET-strip). The last seven are the ones that are either missing or had various bugs in the version of busybox I'm using that prevented the build from working right. Rob -- "One of my most productive days was throwing away 1000 lines of code." - Ken Thompson.
#include <stdio.h> #include <string.h> #include <stdlib.h> #include <fcntl.h> char blah[65536]; #define ROOTPATH "/home/landley/firmware/firmware" int main(int argc, char *argv[], char *env[]) { char *p, *p2; int i, fd; p2 = strrchr(*argv, '/'); if (!p2) p2=*argv; else p2++; p=blah + sprintf(blah, "%s ",p2); for (i=1; i<argc; i++) { p += sprintf(p, "\"%s\" ",argv[i]); } p[-1]='\n'; // Log the command line fd=open(ROOTPATH "/loggy.txt",O_WRONLY|O_CREAT|O_APPEND,0777); write(fd, blah, strlen(blah)); close(fd); // Touch the file that got used. sprintf(blah,ROOTPATH "/used/%s", p2); close(open(blah, O_WRONLY|O_CREAT, 0777)); // Hand off control to the real executable sprintf(blah, ROOTPATH "/handoff/%s", p2); execve(blah, argv, env); // Should never happen, means handoff dir is set up wrong. dprintf(2,"Didn't find %s\n", *argv); exit(1); }