On Thursday 25 March 2010 19:04:46 Rob Landley wrote: > If I do the standard "./configure --disable-werror", it builds qemu-mips > and qemu-system-mips64, but no qemu-mips64. If I tell it "./configure > --disable- werror --target-list-mips64-linux-user", configure completes but > the build breaks because it can't set up the dependencies for that > directory. > > How do I beat a qemu-mips64 out of the qemu source? Apparently, gentoo > manages to build one, but I'm not sure how....
Answer: Gentoo's qemu ebuild file is here: http://sources.gentoo.org/viewcvs.py/gentoo-x86/app- emulation/qemu/qemu-0.11.1.ebuild?rev=1.2&view=log Which has these bits: IUSE_SOFTMMU_TARGETS="${COMMON_TARGETS} ppcemb" IUSE_USER_TARGETS="${COMMON_TARGETS} alpha armeb ppc64abi32 sparc64 sparc32plus" src_prepare() { # avoid fdt till an updated release appears sed -i -e 's:fdt="yes":fdt="no":' configure # prevent docs to get automatically installed sed -i '/$(DESTDIR)$(docdir)/d' Makefile # Alter target makefiles to accept CFLAGS set via flag-o sed -i 's/^\(C\|OP_C\|HELPER_C\)FLAGS=/\1FLAGS+=/' \ Makefile Makefile.target tests/Makefile [[ -x /sbin/paxctl ]] && \ sed -i 's/^VL_LDFLAGS=$/VL_LDFLAGS=-Wl,-z,execheap/' \ Makefile.target # Append CFLAGS while linking sed -i 's/$(LDFLAGS)/$(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS)/' rules.mak epatch "${FILESDIR}/qemu-0.11.0-mips64-user-fix.patch" } Most of which isn't very interesting. Presumably they're getting mips64 from "COMMON_TARGETS", which looks like some kind of ebuild standard plumbing. Gentoo also has a patch directory for qemu: http://sources.gentoo.org/viewcvs.py/gentoo-x86/app-emulation/qemu/files/ And their mips64 patch is here: http://sources.gentoo.org/viewcvs.py/gentoo-x86/app- emulation/qemu/files/qemu-0.11.0-mips64-user-fix.patch?rev=1.1&view=markup Which isn't much: --- qemu-0.11.0.orig/linux-user/main.c 2009-10-23 02:19:57.000000000 +0200 +++ qemu-0.11.0/linux-user/main.c 2009-10-23 02:47:09.000000000 +0200 @@ -1469,6 +1469,8 @@ #ifdef TARGET_MIPS +#define TARGET_QEMU_ESIGRETURN 255 + #define MIPS_SYS(name, args) args, static const uint8_t mips_syscall_args[] = { And that's it. Ok, let's try that out... ./configure --target-list=mips64-linux-user --disable-werror make -j 2 And it died: > GEN config-host.h > Makefile:7: config-devices.mak: No such file or directory > make[1]: *** No rule to make target `config-devices.mak'. Stop. > make: *** [subdir-mips64-linux-user] Error 2 But since the 32 bit version of that file is just a comment, I'm pretty happy doing this: touch mips64-linux-user/config-devices.mak (Dunno where the makefile thinks it should get this from...) So with that, it compiles, with this warning: CC mips64-linux-user/signal.o /home/landley/qemu/git/linux-user/signal.c:2262:3: warning: #warning signal handling not implemented But it's not complaining about system calls. And it gives me a qemu-mips64. Right. Which segfaults immediately running a statically linked "hello world". Running a dynamically linked version it does indeed complain that /lib/ld- uClibc.so.0 isn't there (correct), but the statically linked one segfaults with no output. Huh. Ok, let's scp that to gentoo and try it there... qemu-mips64 ./mips64-hello qemu: uncaught target signal 4 (Illegal instruction) - exiting And running that same hello world binary under system-image-mips64... Works fine. Right, Gentoo includes a qemu-mips64 that _doesn't_work_. (At least not for me.) They fixed the build break, but that's it. False alarm, my bad... Rob -- Latency is more important than throughput. It's that simple. - Linus Torvalds
