Reserve 1GB at the base address of linux nacl_helper for Native Client.

chrome/nacl.gypi

Index: chrome/nacl.gypi
diff --git a/chrome/nacl.gypi b/chrome/nacl.gypi
index 9467359c8582aad8951e1e5cd29da2ec899dad51..72851ad2d4862128b6ea571e7041a055fdb8adc0 100644
--- a/chrome/nacl.gypi
+++ b/chrome/nacl.gypi
@@ -144,10 +144,12 @@
         },
       ],
     }],
-    ['OS=="linux" and touchui == 0', {
+    ['OS=="linux"', {
       'targets': [
         {
-          'target_name': 'nacl_helper',
+          'target_name': 'nacl_helper.so',
+          # 'executable' will be overridden below when we add the -shared
+          # flag; here it prevents gyp from using the --whole-archive flag
           'type': 'executable',
           'include_dirs': [
             '..',
@@ -165,6 +167,32 @@
               ],
             }],
           ],
+          'link_settings': {
+            # NOTE: '-shared' overrides 'executable' above
+            'ldflags': ['-shared',
+                        '-Wl,--version-script=chrome/nacl/nacl_helper_exports.txt',
+                      ],
+          },
+        },
+        {
+          'target_name': 'nacl_helper_bootstrap',
+          'type': 'executable',
+          'dependencies': [
+            'nacl_helper.so',
+          ],
+          'sources': [
+            '../chrome/nacl/nacl_helper_bootstrap_linux.c',
+          ],
+          # TODO(bradchen): Delete the -B argument when Gold supports
+          # -Ttext properly.
+          'link_settings': {
+            'ldflags': ['-B', 'tools/ld_bfd',
+                        # force text segment at 0x10000 (64KB)
+                        '-Wl,-Ttext-segment,10000,-z,max-page-size=0x1000',

[Roland McGrath, 2011/08/15 20:15:51]

Needs a comment that max-page-size=0x1000 is for the benefit of x86_64, where
that's not the default (in the BFD linker).

[Brad Chen, 2011/08/15 23:02:28]

Done.

+                        # reference nacl_helper as a shared library
+                        './out/Debug/nacl_helper.so',
+                      ],
+          },
         },
       ],
     }],