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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/arm/SA1100/serial_UART
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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1The SA1100 serial port had its major/minor numbers officially assigned:
2
3> Date: Sun, 24 Sep 2000 21:40:27 -0700
4> From: H. Peter Anvin <hpa@transmeta.com>
5> To: Nicolas Pitre <nico@CAM.ORG>
6> Cc: Device List Maintainer <device@lanana.org>
7> Subject: Re: device
8>
9> Okay. Note that device numbers 204 and 205 are used for "low density
10> serial devices", so you will have a range of minors on those majors (the
11> tty device layer handles this just fine, so you don't have to worry about
12> doing anything special.)
13>
14> So your assignments are:
15>
16> 204 char Low-density serial ports
17> 5 = /dev/ttySA0 SA1100 builtin serial port 0
18> 6 = /dev/ttySA1 SA1100 builtin serial port 1
19> 7 = /dev/ttySA2 SA1100 builtin serial port 2
20>
21> 205 char Low-density serial ports (alternate device)
22> 5 = /dev/cusa0 Callout device for ttySA0
23> 6 = /dev/cusa1 Callout device for ttySA1
24> 7 = /dev/cusa2 Callout device for ttySA2
25>
26
27If you're not using devfs, you must create those inodes in /dev
28on the root filesystem used by your SA1100-based device:
29
30 mknod ttySA0 c 204 5
31 mknod ttySA1 c 204 6
32 mknod ttySA2 c 204 7
33 mknod cusa0 c 205 5
34 mknod cusa1 c 205 6
35 mknod cusa2 c 205 7
36
37In addition to the creation of the appropriate device nodes above, you
38must ensure your user space applications make use of the correct device
39name. The classic example is the content of the /etc/inittab file where
40you might have a getty process started on ttyS0. In this case:
41
42- replace occurrences of ttyS0 with ttySA0, ttyS1 with ttySA1, etc.
43
44- don't forget to add 'ttySA0', 'console', or the appropriate tty name
45 in /etc/securetty for root to be allowed to login as well.
46
47