README.zeus 2.5 KB

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  1. Storage of the board specific values (ethaddr...)
  2. -------------------------------------------------
  3. The board specific environment variables that should be unique
  4. for each individual board, can be stored in the I2C EEPROM. This
  5. will be done from offset 0x80 with the length of 0x80 bytes. The
  6. following command can be used to store the values here:
  7. => setdef de:20:6a:ed:e2:72 de:20:6a:ed:e2:73 AB0001
  8. ethaddr eth1addr serial#
  9. Now those 3 values are stored into the I2C EEPROM. A CRC is added
  10. to make sure that the values get not corrupted.
  11. SW-Reset Pushbutton handling:
  12. -----------------------------
  13. The SW-reset push button is connected to a GPIO input too. This
  14. way U-Boot can "see" how long the SW-reset was pressed, and a
  15. specific action can be taken. Two different actions are supported:
  16. a) Release after more than 5 seconds and less then 10 seconds:
  17. -> Run POST
  18. Please note, that the POST test will take a while (approx. 1 min
  19. on the 128MByte board). This is mainly due to the system memory
  20. test.
  21. b) Release after more than 10 seconds:
  22. -> Restore factory default settings
  23. The factory default values are restored. The default environment
  24. variables are restored (ipaddr, serverip...) and the board
  25. specific values (ethaddr, eth1addr and serial#) are restored
  26. to the environment from the I2C EEPROM. Also a bootline parameter
  27. is added to the Linux bootline to signal the Linux kernel upon
  28. the next startup, that the factory defaults should be restored.
  29. The command to check this sw-reset status and act accordingly is
  30. => chkreset
  31. This command is added to the default "bootcmd", so that it is called
  32. automatically upon startup.
  33. Also, the 2 LED's are used to indicate the current status of this
  34. command (time passed since pushing the button). When the POST test
  35. will be run, the green LED will be switched off, and when the
  36. factory restore will be initiated, the reg LED will be switched off.
  37. Loggin of POST results:
  38. -----------------------
  39. The results of the POST tests are logged in a logbuffer located at the end
  40. of the onboard memory. It can be accessed with the U-Boot command "log":
  41. => log show
  42. <4>POST memory PASSED
  43. <4>POST cache PASSED
  44. <4>POST cpu PASSED
  45. <4>POST uart PASSED
  46. <4>POST ethernet PASSED
  47. The DENX Linux kernel tree has support for this log buffer included. Exactly
  48. this buffer is used for logging of all kernel messages too. By enabling the
  49. compile time option "CONFIG_LOGBUFFER" this support is enabled. This way you
  50. can access the U-Boot log messages from Linux too.
  51. 2007-08-10, Stefan Roese <sr@denx.de>