From 779e975117a75e91fcebe226a63104dbfb924ab1 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Tue, 14 Aug 2007 14:44:41 +0200 Subject: ppc4xx: Add initial Zeus (PPC405EP) board support Signed-off-by: Stefan Roese --- doc/README.zeus | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 doc/README.zeus (limited to 'doc/README.zeus') diff --git a/doc/README.zeus b/doc/README.zeus new file mode 100644 index 0000000..1848d8c --- /dev/null +++ b/doc/README.zeus @@ -0,0 +1,73 @@ + +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 -- cgit v1.1