According to the description in datasheet of f71889,

"To enable configuration, the entry key 0x87 must be written to
the index port"

 -o 4e 87
 -o 4e 87	(enable configuration)
 -o 4e aa	(disable configuration)
This piece of text appears in most of the datasheet of fintek superio.
It doesnt say it quite clear, but it seems that the 0x87 should
be written twice. I tried on f81865, which is not in the coreboot tree
yet. If the 0x87 is only written once, you can only R/W the index/data
port once. All the subsequent RW will fail. Writing twice will be ok.

Plus, in the superiotool, the function enter_conf_mode_winbond_fintek_ite_8787
also write 8787.

The fintek superio chips seem to enable the UART automatically when the
power is on. So I didnt find it failed to access.

Signed-off-by: Zheng Bao <>
Acked-by: Stefan Reinauer <>

git-svn-id: svn:// 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
4 files changed
tree: 008f642a7bded1dd1460b7fabc9edd4a8f662e10
  1. documentation/
  2. payloads/
  3. src/
  4. util/
  6. Makefile