Gllin

Revision as of 00:20, 10 November 2007

gllin is an userpsace driver for a hammerhead chip. It was distributed on phase1 openmokos.

Unfortunately, it is an OABI binary, and not even static one, so lots of stuff is needed for it to work. For security reasons, and for compatibility with EABI userland, it is probably best to run it in chroot. Zdanek's wrote an article how to put that together.

The changeroot trick

Your chroot will need to contain following files:

./dev
./dev/zero
./dev/ttySAC1
./etc
./etc/hosts
./etc/nsswitch.conf
./etc/host.conf
./lib
./lib/libm.so.6
./lib/libpthread-2.5.so
./lib/libnss_files.so.2
./lib/libnss_compat-2.5.so
./lib/libnss_mdns6_minimal.so.2
./lib/libanl-2.5.so
./lib/libgcc_s.so.1
./lib/libutil-2.5.so
./lib/libmemusage.so
./lib/libm-2.5.so
./lib/libc-2.5.so
./lib/libnss_mdns_minimal.so.2
./lib/libBrokenLocale.so.1
./lib/libnss_mdns4_minimal.so.2
./lib/libpthread.so.0
./lib/librt-2.5.so
./lib/libdl-2.5.so
./lib/libutil.so.1
./lib/libthread_db-1.0.so
./lib/libcrypt-2.5.so
./lib/libnss_compat.so.2
./lib/libnss_mdns4.so.2
./lib/libnss_mdns6.so.2
./lib/ld-2.5.so
./lib/libcidn.so.1
./lib/libthread_db.so.1
./lib/libnss_files-2.5.so
./lib/libanl.so.1
./lib/libcrypt.so.1
./lib/libnss_dns-2.5.so
./lib/ld-linux.so.2
./lib/libnss_mdns.so.2
./lib/libdl.so.2
./lib/libnss_dns.so.2
./lib/libc.so.6
./lib/librt.so.1
./lib/libcidn-2.5.so
./lib/libBrokenLocale-2.5.so
./log
./tmp
./tmp/nmeaNP
./usr
./usr/lib
./usr/lib/libstdc++.so.6
./usr/lib/libstdc++.so.6.0.8
./gllin
./sys

...and you"ll want to mount /sys there. Then, to get gps to work, do:

root@fic-gta01:/chroot$ cat /chroot/tmp/nmeaNP &
root@fic-gta01:/chroot$ chroot /chroot/ gllin -low 1
root@fic-gta01:/chroot$ chroot /chroot/ gllin -periodic 1

The ld-linux trick

you need the following files:

bin/gllin
bin/gllin.sh
lib/ld-linux.so.2
lib/libc.so.6
lib/libgcc_s.so.1
lib/libm.so.6
lib/libnss_dns.so.2
lib/libnss_files.so.2
lib/libpthread.so.0
lib/libresolv.so.2
lib/librt.so.1
lib/libstdc++.so.6
lib/libutil.so.1

the file bin/gllin.sh contains:

#!/bin/sh
`pwd`/lib/ld-linux.so.2 --library-path `pwd`/lib `pwd`/bin/gllin -low 5
test -p /tmp/nmeaNP || ( rm -f /tmp/nmeaNP && mknod /tmp/nmeaNP p )
`pwd`/lib/ld-linux.so.2 --library-path `pwd`/lib `pwd`/bin/gllin -periodic 3

be shure to start at least a `cat /tmp/nmeaNP` somewhere.

Strange messages

the message

Stack size 8864 bytes (9 KB)

means, nobody is reading on the pipe /tmp/nmeaNP, you probably forgot to start the `cat ...`. the message

gllin: early exit(3) in halInit()/681

is issued by the low-level hardware test but gllin works fine afterwords.