illumos gate

usr/src/boot/sys/boot/i386/isoboot/Makefile references btxld directly instead of correctly using the macro $(BTXLD) that is used everywhere else. This can break the build or generate the wrong results in certain build-time tools configurations if btxld is not on $PATH or $PATH contains a different version of the tool. The trivial fix is as follows:

diff --git a/usr/src/boot/sys/boot/i386/isoboot/Makefile b/usr/src/boot/sys/boot/i386/isoboot/Makefile
index 2a0992e5cc..f2e20b2372 100644
--- a/usr/src/boot/sys/boot/i386/isoboot/Makefile
+++ b/usr/src/boot/sys/boot/i386/isoboot/Makefile
@@ -61,7 +61,7 @@ OBJS= mb_header.o isoboot.o sio.o drv.o cons.o gptldr.o
 CLEANFILES += isoboot

 isoboot: gptldr.bin isoboot.bin $(BTXKERN)
-       btxld -v -E $(ORG2) -f bin -b $(BTXKERN) -V $(BOOT_VERSION) -l \
+       $(BTXLD) -v -E $(ORG2) -f bin -b $(BTXKERN) -V $(BOOT_VERSION) -l \
                gptldr.bin -o $@ isoboot.bin
        @set -- `ls -l $@`; x=$$(($(ISOBOOTSIZE)-$$5)); \
            echo "$$x bytes available"; test $$x -ge 0