Two things

1.  When building a .so I get undefined reference errors, yet the .so is built.

Here is the GCC output from the rm of the .so onward:

C:/QNX632/host/win32/x86/usr/bin/rm -f  C:/ARI/IDDAerospace/Code/devn/mpc85xx/ppc/dll.be.g/devn-mpc85xx-mpc85xx_g.so
C:/QNX632/host/win32/x86/usr/bin/qcc -V3.3.5,gcc_ntoppc -Wl,--no-keep-memory  -shared -Wl,-hdevn-mpc85xx-mpc85xx_g.so  -
oC:/ARI/IDDAerospace/Code/devn/mpc85xx/ppc/dll.be.g/devn-mpc85xx-mpc85xx_g.so -g   detect.o    devctl.o    mii.o    
mpc85xx.o    receive.o    shutdown.o    transmit.o  -L. -LC:/QNX632/target/qnx6/ppcbe/lib/gcc/3.3.5 -LC:/QNX632/target/
qnx6/ppcbe/lib -LC:/QNX632/target/qnx6/ppcbe/usr/lib     -EB  -g    -Wl,-Bsymbolic        
detect.o: In function `mpc_parse_options':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:87: undefined reference to `nic_parse_options'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:156: undefined reference to `nic_slogf'
detect.o: In function `mpc_create_instance':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:268: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:295: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:297: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:302: undefined reference to `nic_slogf'
detect.o:C:/ARI/IDDAerospace/Code/devn/mpc85xx/detect.c:307: more undefined references to `nic_slogf' follow
mii.o: In function `mpc_mii_callback':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:107: undefined reference to `MDI_GetActiveMedia'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:110: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:114: undefined reference to `MDI_AutoNegotiate'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:117: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:176: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:196: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:200: undefined reference to `MDI_AutoNegotiate'
mii.o: In function `mpc_init_phy':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:228: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:233: undefined reference to `MDI_Register_Extended'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:243: undefined reference to `MDI_FindPhy'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:244: undefined reference to `MDI_InitPhy'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:246: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:249: undefined reference to `MDI_ResetPhy'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:254: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:269: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:277: undefined reference to `MDI_AutoNegotiate'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:279: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:283: undefined reference to `MDI_EnableMonitor'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:285: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:303: undefined reference to `MDI_SetAdvert'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:308: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:315: undefined reference to `nic_slogf'
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mii.c:358: undefined reference to `MDI_EnableMonitor'
mpc85xx.o: In function `mpc_event_handler':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mpc85xx.c:319: undefined reference to `MDI_MonitorPhy'
mpc85xx.o: In function `mpc_init_memory':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mpc85xx.c:400: undefined reference to `nic_slogf'
mpc85xx.o: In function `read_phys_addr':
C:/ARI/IDDAerospace/Code/devn/mpc85xx/mpc85xx.c:498: undefined reference to `nic_slogf'
mpc85xx.o: In function...