本人升级到12.04，但是工作需要，编译android 4.0的代码。出现以下错误，目前还没解决。请教各位大侠，知道的告诉小弟，谢谢啊。

host Executable: nvflash (out/host/linux-x86/obj/EXECUTABLES/nvflash_intermediates/nvflash)
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsLibraryLoad':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:1646: undefined reference to `dlopen'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsLibraryGetSymbol':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:1670: undefined reference to `dlsym'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsLibraryUnload':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:1684: undefined reference to `dlclose'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsTlsAllocInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2166: undefined reference to `pthread_key_create'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsTlsFreeInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2177: undefined reference to `pthread_key_delete'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsTlsGetInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2185: undefined reference to `pthread_getspecific'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsTlsSetInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2191: undefined reference to `pthread_setspecific'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsTlsAddTerminatorInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2279: undefined reference to `pthread_getspecific'
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2288: undefined reference to `pthread_setspecific'
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2272: undefined reference to `pthread_key_create'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsThreadJoinInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2387: undefined reference to `pthread_join'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `NvOsThreadCreateInternal':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:2345: undefined reference to `pthread_create'
out/host/linux-x86/obj/STATIC_LIBRARIES/libnvos_intermediates/libnvos.a(nvos_linux.o): In function `nvos_fini':
/home/bryant/QU001/vendor/nvidia/tegra/prebuilt/ventana/../../core/utils/nvos/linux/nvos_linux.c:3113: undefined reference to `pthread_key_delete'
collect2: ld 返回 1
make: *** [out/host/linux-x86/obj/EXECUTABLES/nvflash_intermediates/nvflash] 错误 1

到这里，我编译失败了。
亲们，再次感谢。