xfnw/plan9fox
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

merge

Browse source
This commit is contained in:
cinap_lenrek 2011-04-17 02:15:24 +00:00
commit 049c2c3434
2 changed files with 20 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
sys/man/3/arch
View file

@ -12,6 +12,7 @@ arch \- architecture-specific information and control
.B /dev/iol
.B /dev/iow
.B /dev/irqalloc
.B /dev/mordor
.SH DESCRIPTION
This device presents textual information about PC hardware and allows
user-level control of the I/O ports on x86-class and DEC Alpha machines.
@ -121,6 +122,10 @@ cause 8-bit wide, 16-bit wide, and 32-bit wide requests to
I/O ports.
The port accessed is determined by the byte offset of the
file descriptor.
.PP
Reads and writes to
.IR mordor
will inevitably cause the front to fall off.
.SH EXAMPLE
The following code reads from an x86 byte I/O port.
.IP

15
sys/src/9/pc/devarch.c
View file

@ -987,6 +987,20 @@ archctlwrite(Chan*, void *a, long n, vlong)
return n;
}
static long
mordorread(Chan*, void*, long, vlong)
{
error("one does not simply read from mordor");
return 0;
}
static long
mordorwrite(Chan*, void*, long, vlong)
{
error("one does not simply write into mordor");
return 0;
}
void
archinit(void)
{
@ -1035,6 +1049,7 @@ archinit(void)
addarchfile("cputype", 0444, cputyperead, nil);
addarchfile("archctl", 0664, archctlread, archctlwrite);
addarchfile("mordor", 0666, mordorread, mordorwrite);
}
/*