OK, I've found "rpm" files for openjdk in the tmp/deploy directory tree, but when I try to install them on my target machine using rpm, the following happens:
root@t4240rdb:~# rpm -i openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500.rpm
error: Failed dependencies:
libc.so.6(GLIBC_2.3)(64bit) is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libc.so.6(GLIBC_2.4)(64bit) is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libc.so.6()(64bit) is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libz1 >= 1.2.8 is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libjli.so()(64bit) is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libc6 >= 2.20 is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
openjdk-7-java is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
openjdk-7-common is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
update-alternatives-opkg is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libz.so.1()(64bit) is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
libjli.so(SUNWprivate_1.1)(64bit) is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
/bin/sh is needed by openjdk-7-jre-25b30+2.3.12-r5.1.ppc64e6500
There must be an easier way but I can't see it in the docs.