Add the ability to not report an I2C POST error for a set of given I2C
addresses on bootup. This is useful for cases when a device may or may
not be present, and neither case is considered an error. For example:
- Some form factors such as XMC and Compact PCI Express have an I2C
EEPROM whose address changes based on geographical address. Eg
installed in one slot its EEPROM address is, 0x50, in another its
0x51, etc. This allows multiple devices to have their EEPROMs present
on the same I2C bus. Thus the I2C devices present for an XMC or
CPCIe card depend on if and where other cards are installed in the
same system.
- Some cards have optional I2C devices. Eg one hardware build
configuration has different I2C devices than another and software
can't determine if the optional device should be present or not.
- Some cards have optional daughtercards with I2C devices on them.
- I2C EEPROMs address range depends on their size. Its possible to
support differently size EEPROMs by only probing the EEPROM's base
address and ignoring the other addresses that are impacted by its
size.
A new CONFIG_SYS_POST_I2C_IGNORES define has been added which specifies
a list of I2C addresses for the I2C POST to ignore.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Acked-by: Heiko Schocher <hs@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Storage of the board specific values (ethaddr...)
-------------------------------------------------
The board specific environment variables that should be unique
for each individual board, can be stored in the I2C EEPROM. This
will be done from offset 0x80 with the length of 0x80 bytes. The
following command can be used to store the values here:
=> setdef de:20:6a:ed:e2:72 de:20:6a:ed:e2:73 AB0001
ethaddr eth1addr serial#
Now those 3 values are stored into the I2C EEPROM. A CRC is added
to make sure that the values get not corrupted.
SW-Reset Pushbutton handling:
-----------------------------
The SW-reset push button is connected to a GPIO input too. This
way U-Boot can "see" how long the SW-reset was pressed, and a
specific action can be taken. Two different actions are supported:
a) Release after more than 5 seconds and less then 10 seconds:
-> Run POST
Please note, that the POST test will take a while (approx. 1 min
on the 128MByte board). This is mainly due to the system memory
test.
b) Release after more than 10 seconds:
-> Restore factory default settings
The factory default values are restored. The default environment
variables are restored (ipaddr, serverip...) and the board
specific values (ethaddr, eth1addr and serial#) are restored
to the environment from the I2C EEPROM. Also a bootline parameter
is added to the Linux bootline to signal the Linux kernel upon
the next startup, that the factory defaults should be restored.
The command to check this sw-reset status and act accordingly is
=> chkreset
This command is added to the default "bootcmd", so that it is called
automatically upon startup.
Also, the 2 LED's are used to indicate the current status of this
command (time passed since pushing the button). When the POST test
will be run, the green LED will be switched off, and when the
factory restore will be initiated, the reg LED will be switched off.
Loggin of POST results:
-----------------------
The results of the POST tests are logged in a logbuffer located at the end
of the onboard memory. It can be accessed with the U-Boot command "log":
=> log show
<4>POST memory PASSED
<4>POST cache PASSED
<4>POST cpu PASSED
<4>POST uart PASSED
<4>POST ethernet PASSED
The DENX Linux kernel tree has support for this log buffer included. Exactly
this buffer is used for logging of all kernel messages too. By enabling the
compile time option "CONFIG_LOGBUFFER" this support is enabled. This way you
can access the U-Boot log messages from Linux too.
2007-08-10, Stefan Roese <sr@denx.de>