how to make a git-format patch

Hi list,

When I use GIT to generate a patch, I can use git-diff, if one file
changed, I can get the following patch:
=================================

diff --git a/net/packet/Kconfig b/net/packet/Kconfig
index 34ff93f..959c272 100644
--- a/net/packet/Kconfig
+++ b/net/packet/Kconfig

@@ -17,7 +17,7 @@ config PACKET

 config PACKET_MMAP
        bool "Packet socket: mmapped IO"
-       depends on PACKET
+       depends on PACKET && MMU
        help
          If you say Y here, the Packet protocol driver will use an IO
          mechanism that results in faster communication.

=================================
But I saw most of the git-format patches have a header in the front of
the patch file, like:
=================================
 * Added xxxxxx support

Signed-off-by: xxxxxxxx <redacted>
---

 net/packet/Kconfig |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/net/packet/Kconfig b/net/packet/Kconfig
index 34ff93f..959c272 100644
--- a/net/packet/Kconfig
+++ b/net/packet/Kconfig

----snip----

=================================

Just want to know how this kind of patch format generated.
Thanks for any hints.

Regards,
-Aubrey