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