Try building and uploading MIPS toolchain on one of the buildbots.

buildbot/buildbot_selector.py

 #!/usr/bin/python
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import json
 import os
 import subprocess
 import sys
 
@@ skipping 124 matching lines @@
                    'coverage 32 newlib --coverage'),
     # Clang trybots.
     'nacl-precise_64-newlib-dbg-clang':
         python + ' buildbot/buildbot_standard.py dbg 64 newlib --clang',
     'nacl-mac10.6-newlib-dbg-clang':
         python + ' buildbot/buildbot_standard.py dbg 32 newlib --clang',
     # Pnacl main trybots
     'nacl-precise_64-newlib-arm_qemu-pnacl':
         bash + ' buildbot/buildbot_pnacl.sh mode-trybot-qemu arm',
     'nacl-precise_64-newlib-x86_32-pnacl':
-         python + ' buildbot/buildbot_pnacl.py opt 32 pnacl',
+        #  python + ' buildbot/buildbot_pnacl.py opt 32 pnacl',
+        bash + ' buildbot/buildbot_pnacl.sh mode-trybot-qemu mips32',
     'nacl-precise_64-newlib-x86_64-pnacl':
-         python + ' buildbot/buildbot_pnacl.py opt 64 pnacl',
+     #    python + ' buildbot/buildbot_pnacl.py opt 64 pnacl',
+     #     bash + ' buildbot/buildbot_toolchain_mips_trusted.sh',
+        bash + ' buildbot/buildbot_pnacl.sh mode-trybot-qemu mips32',
     'nacl-precise_64-newlib-mips-pnacl':
-        echo + ' "TODO(mseaborn): add mips"',
+        # echo + ' "TODO(mseaborn): add mips",
+        bash + ' buildbot/buildbot_pnacl.sh mode-trybot-qemu mips32',
     'nacl-arm_opt_panda':
         bash + ' buildbot/buildbot_pnacl.sh mode-buildbot-arm-try',
     'nacl-arm_hw_opt_panda':
         bash + ' buildbot/buildbot_pnacl.sh mode-buildbot-arm-hw-try',
     'nacl-mac10.8_newlib_opt_pnacl':
         python + ' buildbot/buildbot_pnacl.py opt 32 pnacl',
     'nacl-win7_64_newlib_opt_pnacl':
         python + ' buildbot/buildbot_pnacl.py opt 64 pnacl',
     # Pnacl spec2k trybots
     'nacl-precise_64-newlib-x86_32-pnacl-spec':
@@ skipping 259 matching lines @@
         cmd,
     ])
 
   print "%s runs: %s\n" % (builder, cmd)
   retcode = subprocess.call(cmd, env=env, shell=True)
   sys.exit(retcode)
 
 
 if __name__ == '__main__':
   Main()