Date: Fri, 14 Oct 2005 19:27:00 -0700 (PDT) From: Doug Ambrisko <ambrisko@ambrisko.com> To: Dan Langille <dan@langille.org> Cc: freebsd-emulation@freebsd.org Subject: Re: cross platform building under emulation Message-ID: <200510150227.j9F2R0Yl081732@ambrisko.com> In-Reply-To: <434EC854.31435.8209C41D@localhost>
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Dan Langille writes:
| Daris has got me thinking about unpacking 4.9-release/bin into a
| directory, and then doing a chroot.
That sort-of works. I've done some setups for companies and get
iteratively better solutions. I copy over some host bins & libs
into special directories so mount, ps etc can be run from inside.
I also have mods to libc so that uname & getosreldate so it can
be set via env. variables so pkg_add, autoconf etc picks up the
right stuff. Now this is a little trickier for old version of
libc that I haven't modified locally yet so I build a stub lib.
of these in the chroot then load this then LD_PRELOAD. If you don't
then some things get messed up.
This lets me build on a FreeBSD 6.X/amd64 host for FreeBSD 4.X/386,
FreeBSD amd64 etc. I've also at times loaded in the Linux tools and
made that work so I could build Linux bins in chroots.
I hope to commit my changes to getosreldate(3) and uname(3).
This mirrors the env. variables in /usr/bin/uname.
Index: __xuname.c
===================================================================
RCS file: /cvs/src/lib/libc/gen/__xuname.c,v
retrieving revision 1.9
diff -u -p -r1.9 __xuname.c
--- __xuname.c 1 Feb 2002 00:57:29 -0000 1.9
+++ __xuname.c 15 Oct 2005 02:24:05 -0000
@@ -41,13 +41,15 @@ __FBSDID("$FreeBSD$");
#include <sys/sysctl.h>
#include <sys/utsname.h>
#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
int
__xuname(int namesize, void *namebuf)
{
int mib[2], rval;
size_t len;
- char *p;
+ char *p, *u_s, *u_r, *u_v, *u_m;
int oerrno;
struct xutsname {
char sysname[namesize]; /* Name of this OS. */
@@ -57,18 +59,27 @@ __xuname(int namesize, void *namebuf)
char machine[namesize]; /* Hardware type. */
} *name;
+ u_s = getenv("UNAME_s");
+ u_r = getenv("UNAME_r");
+ u_v = getenv("UNAME_v");
+ u_m = getenv("UNAME_m");
+
name = (struct xutsname *)namebuf;
rval = 0;
- mib[0] = CTL_KERN;
- mib[1] = KERN_OSTYPE;
- len = sizeof(name->sysname);
- oerrno = errno;
- if (sysctl(mib, 2, &name->sysname, &len, NULL, 0) == -1) {
- if(errno == ENOMEM)
- errno = oerrno;
- else
- rval = -1;
+ if (u_s)
+ strncpy(name->sysname, u_s, sizeof(name->sysname));
+ else {
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_OSTYPE;
+ len = sizeof(name->sysname);
+ oerrno = errno;
+ if (sysctl(mib, 2, &name->sysname, &len, NULL, 0) == -1) {
+ if(errno == ENOMEM)
+ errno = oerrno;
+ else
+ rval = -1;
+ }
}
name->sysname[sizeof(name->sysname) - 1] = '\0';
@@ -84,28 +95,36 @@ __xuname(int namesize, void *namebuf)
}
name->nodename[sizeof(name->nodename) - 1] = '\0';
- mib[0] = CTL_KERN;
- mib[1] = KERN_OSRELEASE;
- len = sizeof(name->release);
- oerrno = errno;
- if (sysctl(mib, 2, &name->release, &len, NULL, 0) == -1) {
- if(errno == ENOMEM)
- errno = oerrno;
- else
- rval = -1;
+ if (u_r)
+ strncpy(name->sysname, u_r, sizeof(name->sysname));
+ else {
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_OSRELEASE;
+ len = sizeof(name->release);
+ oerrno = errno;
+ if (sysctl(mib, 2, &name->release, &len, NULL, 0) == -1) {
+ if(errno == ENOMEM)
+ errno = oerrno;
+ else
+ rval = -1;
+ }
}
name->release[sizeof(name->release) - 1] = '\0';
/* The version may have newlines in it, turn them into spaces. */
- mib[0] = CTL_KERN;
- mib[1] = KERN_VERSION;
- len = sizeof(name->version);
- oerrno = errno;
- if (sysctl(mib, 2, &name->version, &len, NULL, 0) == -1) {
- if (errno == ENOMEM)
- errno = oerrno;
- else
- rval = -1;
+ if (u_v)
+ strncpy(name->sysname, u_v, sizeof(name->sysname));
+ else {
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_VERSION;
+ len = sizeof(name->version);
+ oerrno = errno;
+ if (sysctl(mib, 2, &name->version, &len, NULL, 0) == -1) {
+ if (errno == ENOMEM)
+ errno = oerrno;
+ else
+ rval = -1;
+ }
}
name->version[sizeof(name->version) - 1] = '\0';
for (p = name->version; len--; ++p) {
@@ -117,15 +136,19 @@ __xuname(int namesize, void *namebuf)
}
}
- mib[0] = CTL_HW;
- mib[1] = HW_MACHINE;
- len = sizeof(name->machine);
- oerrno = errno;
- if (sysctl(mib, 2, &name->machine, &len, NULL, 0) == -1) {
- if (errno == ENOMEM)
- errno = oerrno;
- else
- rval = -1;
+ if (u_m)
+ strncpy(name->sysname, u_m, sizeof(name->sysname));
+ else {
+ mib[0] = CTL_HW;
+ mib[1] = HW_MACHINE;
+ len = sizeof(name->machine);
+ oerrno = errno;
+ if (sysctl(mib, 2, &name->machine, &len, NULL, 0) == -1) {
+ if (errno == ENOMEM)
+ errno = oerrno;
+ else
+ rval = -1;
+ }
}
name->machine[sizeof(name->machine) - 1] = '\0';
return (rval);
Index: getosreldate.c
===================================================================
RCS file: /cvs/src/lib/libc/gen/getosreldate.c,v
retrieving revision 1.7
diff -u -p -r1.7 getosreldate.c
--- getosreldate.c 12 Sep 2005 19:52:41 -0000 1.7
+++ getosreldate.c 15 Oct 2005 02:24:05 -0000
@@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/sysctl.h>
+#include <stdlib.h>
#include <osreldate.h>
@@ -49,10 +50,16 @@ getosreldate(void)
size_t size;
int value;
- mib[0] = CTL_KERN;
- mib[1] = KERN_OSRELDATE;
- size = sizeof value;
- if (sysctl(mib, 2, &value, &size, NULL, 0) == -1)
- return (-1);
+ char *temp;
+
+ if ((temp = getenv("OSVERSION")))
+ value = atoi(temp);
+ else {
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_OSRELDATE;
+ size = sizeof value;
+ if (sysctl(mib, 2, &value, &size, NULL, 0) == -1)
+ return (-1);
+ }
return (value);
}
Does anyone have any objections?
Thanks,
Doug A.
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