serial_UART 1.8 KB

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  1. The SA1100 serial port had its major/minor numbers officially assigned:
  2. > Date: Sun, 24 Sep 2000 21:40:27 -0700
  3. > From: H. Peter Anvin <hpa@transmeta.com>
  4. > To: Nicolas Pitre <nico@CAM.ORG>
  5. > Cc: Device List Maintainer <device@lanana.org>
  6. > Subject: Re: device
  7. >
  8. > Okay. Note that device numbers 204 and 205 are used for "low density
  9. > serial devices", so you will have a range of minors on those majors (the
  10. > tty device layer handles this just fine, so you don't have to worry about
  11. > doing anything special.)
  12. >
  13. > So your assignments are:
  14. >
  15. > 204 char Low-density serial ports
  16. > 5 = /dev/ttySA0 SA1100 builtin serial port 0
  17. > 6 = /dev/ttySA1 SA1100 builtin serial port 1
  18. > 7 = /dev/ttySA2 SA1100 builtin serial port 2
  19. >
  20. > 205 char Low-density serial ports (alternate device)
  21. > 5 = /dev/cusa0 Callout device for ttySA0
  22. > 6 = /dev/cusa1 Callout device for ttySA1
  23. > 7 = /dev/cusa2 Callout device for ttySA2
  24. >
  25. You must create those inodes in /dev on the root filesystem used
  26. by your SA1100-based device:
  27. mknod ttySA0 c 204 5
  28. mknod ttySA1 c 204 6
  29. mknod ttySA2 c 204 7
  30. mknod cusa0 c 205 5
  31. mknod cusa1 c 205 6
  32. mknod cusa2 c 205 7
  33. In addition to the creation of the appropriate device nodes above, you
  34. must ensure your user space applications make use of the correct device
  35. name. The classic example is the content of the /etc/inittab file where
  36. you might have a getty process started on ttyS0. In this case:
  37. - replace occurrences of ttyS0 with ttySA0, ttyS1 with ttySA1, etc.
  38. - don't forget to add 'ttySA0', 'console', or the appropriate tty name
  39. in /etc/securetty for root to be allowed to login as well.