diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index c824544..2b4169e 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -23,88 +23,116 @@
 #include <sys/cdefs.h>
 #include <sys/types.h>  /* for off64_t */
 
+/**
+ * \file
+ * Advanced dynamic library opening support. Most users will want to use
+ * the standard [dlopen(3)](http://man7.org/linux/man-pages/man3/dlopen.3.html)
+ * functionality in `<dlfcn.h>` instead.
+ */
+
 __BEGIN_DECLS
 
-/* bitfield definitions for android_dlextinfo.flags */
+/** Bitfield definitions for `android_dlextinfo::flags`. */
 enum {
-  /* When set, the reserved_addr and reserved_size fields must point to an
+  /**
+   * When set, the `reserved_addr` and `reserved_size` fields must point to an
    * already-reserved region of address space which will be used to load the
-   * library if it fits. If the reserved region is not large enough, the load
-   * will fail.
+   * library if it fits.
+   *
+   * If the reserved region is not large enough, loading will fail.
    */
   ANDROID_DLEXT_RESERVED_ADDRESS      = 0x1,
 
-  /* As DLEXT_RESERVED_ADDRESS, but if the reserved region is not large enough,
+  /**
+   * Like `ANDROID_DLEXT_RESERVED_ADDRESS`, but if the reserved region is not large enough,
    * the linker will choose an available address instead.
    */
   ANDROID_DLEXT_RESERVED_ADDRESS_HINT = 0x2,
 
-  /* When set, write the GNU RELRO section of the mapped library to relro_fd
+  /**
+   * When set, write the GNU RELRO section of the mapped library to `relro_fd`
    * after relocation has been performed, to allow it to be reused by another
    * process loading the same library at the same address. This implies
-   * ANDROID_DLEXT_USE_RELRO.
+   * `ANDROID_DLEXT_USE_RELRO`.
+   *
+   * This is mainly useful for the system WebView implementation.
    */
   ANDROID_DLEXT_WRITE_RELRO           = 0x4,
 
-  /* When set, compare the GNU RELRO section of the mapped library to relro_fd
+  /**
+   * When set, compare the GNU RELRO section of the mapped library to `relro_fd`
    * after relocation has been performed, and replace any relocated pages that
    * are identical with a version mapped from the file.
+   *
+   * This is mainly useful for the system WebView implementation.
    */
   ANDROID_DLEXT_USE_RELRO             = 0x8,
 
-  /* Instruct dlopen to use library_fd instead of opening file by name.
+  /**
+   * Use `library_fd` instead of opening the file by name.
    * The filename parameter is still used to identify the library.
    */
   ANDROID_DLEXT_USE_LIBRARY_FD        = 0x10,
 
-  /* If opening a library using library_fd read it starting at library_fd_offset.
-   * This flag is only valid when ANDROID_DLEXT_USE_LIBRARY_FD is set.
+  /**
+   * If opening a library using `library_fd` read it starting at `library_fd_offset`.
+   * This is mainly useful for loading a library stored within another file (such as uncompressed
+   * inside a ZIP archive).
+   * This flag is only valid when `ANDROID_DLEXT_USE_LIBRARY_FD` is set.
    */
   ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET    = 0x20,
 
-  /* When set, do not check if the library has already been loaded by file stat(2)s.
+  /**
+   * When set, do not use `stat(2)` to check if the library has already been loaded.
    *
    * This flag allows forced loading of the library in the case when for some
    * reason multiple ELF files share the same filename (because the already-loaded
    * library has been removed and overwritten, for example).
    *
-   * Note that if the library has the same dt_soname as an old one and some other
-   * library has the soname in DT_NEEDED list, the first one will be used to resolve any
+   * Note that if the library has the same `DT_SONAME` as an old one and some other
+   * library has the soname in its `DT_NEEDED` list, the first one will be used to resolve any
    * dependencies.
    */
   ANDROID_DLEXT_FORCE_LOAD = 0x40,
 
-  /* When set, if the minimum p_vaddr of the ELF file's PT_LOAD segments is non-zero,
+  /**
+   * When set, if the minimum `p_vaddr` of the ELF file's `PT_LOAD` segments is non-zero,
    * the dynamic linker will load it at that address.
    *
    * This flag is for ART internal use only.
    */
   ANDROID_DLEXT_FORCE_FIXED_VADDR = 0x80,
 
-  /* Instructs dlopen to load the library at the address specified by reserved_addr.
+  /**
+   * Instructs dlopen to load the library at the address specified by reserved_addr.
    *
-   * The difference between ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS and ANDROID_DLEXT_RESERVED_ADDRESS
-   * is that for ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS the linker reserves memory at reserved_addr
-   * whereas for ANDROID_DLEXT_RESERVED_ADDRESS the linker relies on the caller to reserve the memory.
+   * The difference between `ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS` and
+   * `ANDROID_DLEXT_RESERVED_ADDRESS` is that for `ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS` the linker
+   * reserves memory at `reserved_addr` whereas for `ANDROID_DLEXT_RESERVED_ADDRESS` the linker
+   * relies on the caller to reserve the memory.
    *
-   * This flag can be used with ANDROID_DLEXT_FORCE_FIXED_VADDR; when ANDROID_DLEXT_FORCE_FIXED_VADDR
-   * is set and load_bias is not 0 (load_bias is min(p_vaddr) of PT_LOAD segments) this flag is ignored.
-   * This is implemented this way because the linker has to pick one address over the other and this
-   * way is more convenient for art. Note that ANDROID_DLEXT_FORCE_FIXED_VADDR does not generate
-   * an error when min(p_vaddr) is 0.
+   * This flag can be used with `ANDROID_DLEXT_FORCE_FIXED_VADDR`. When
+   * `ANDROID_DLEXT_FORCE_FIXED_VADDR` is set and `load_bias` is not 0 (`load_bias` is the
+   * minimum `p_vaddr` of all `PT_LOAD` segments) this flag is ignored because the linker has to
+   * pick one address over the other and this way is more convenient for ART.
+   * Note that `ANDROID_DLEXT_FORCE_FIXED_VADDR` does not generate an error when the minimum
+   * `p_vaddr` is 0.
    *
-   * Cannot be used with ANDROID_DLEXT_RESERVED_ADDRESS or ANDROID_DLEXT_RESERVED_ADDRESS_HINT.
+   * Cannot be used with `ANDROID_DLEXT_RESERVED_ADDRESS` or `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`.
    *
    * This flag is for ART internal use only.
    */
   ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS = 0x100,
 
-  /* This flag used to load library in a different namespace. The namespace is
-   * specified in library_namespace.
+  /**
+   * This flag used to load library in a different namespace. The namespace is
+   * specified in `library_namespace`.
+   *
+   * This flag is for internal use only (since there is no NDK API for namespaces).
    */
   ANDROID_DLEXT_USE_NAMESPACE = 0x200,
 
-  /* Mask of valid bits */
+  /** Mask of valid bits. */
   ANDROID_DLEXT_VALID_FLAG_BITS       = ANDROID_DLEXT_RESERVED_ADDRESS |
                                         ANDROID_DLEXT_RESERVED_ADDRESS_HINT |
                                         ANDROID_DLEXT_WRITE_RELRO |
@@ -119,19 +147,36 @@
 
 struct android_namespace_t;
 
+/** Used to pass Android-specific arguments to `android_dlopen_ext`. */
 typedef struct {
+  /** A bitmask of `ANDROID_DLEXT_` enum values. */
   uint64_t flags;
+
+  /** Used by `ANDROID_DLEXT_RESERVED_ADDRESS` and `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. */
   void*   reserved_addr;
+  /** Used by `ANDROID_DLEXT_RESERVED_ADDRESS` and `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. */
   size_t  reserved_size;
+
+  /** Used by `ANDROID_DLEXT_WRITE_RELRO` and `ANDROID_DLEXT_USE_RELRO`. */
   int     relro_fd;
+
+  /** Used by `ANDROID_DLEXT_USE_LIBRARY_FD`. */
   int     library_fd;
+  /** Used by `ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET` */
   off64_t library_fd_offset;
+
+  /** Used by `ANDROID_DLEXT_USE_NAMESPACE`. */
   struct android_namespace_t* library_namespace;
 } android_dlextinfo;
 
+/**
+ * Opens the given library. The `__filename` and `__flags` arguments are
+ * the same as for [dlopen(3)](http://man7.org/linux/man-pages/man3/dlopen.3.html),
+ * with the Android-specific flags supplied via the `flags` member of `__info`.
+ */
 void* android_dlopen_ext(const char* __filename, int __flags, const android_dlextinfo* __info)
   __INTRODUCED_IN(21);
 
 __END_DECLS
 
-#endif /* __ANDROID_DLEXT_H__ */
+#endif