INB(10.2) INB(10.2)
NAME
inb, ins, inl, outb, outs, outl, insb, inss, insl, outsb, outss, outsl
- programmed I/O
SYNOPSIS
int inb(int port)
ushort ins(int port)
ulong inl(int port)
void outb(int port, int value)
void outs(int port, ushort value)
void outl(int port, ulong value)
void insb(int port, void *address, int count)
void inss(int port, void *address, int count)
void insl(int port, void *address, int count)
void outsb(int port, void *address, int count)
void outss(int port, void *address, int count)
void outsl(int port, void *address, int count)
DESCRIPTION
The x86 implementation provides functions to allow kernel code written
in C to access the I/O address space. On several other architectures
such as the PowerPC and Strongarm, the platform-dependent code provides
similar functions to access devices with an I/O space interface, even
when that is memory mapped, to encourage portability of device drivers.
Inb, ins and inl apply the corresponding hardware instruction to fetch
the next byte, short or long from the I/O port. Outb, outs and outl
output a value to the I/O port.
The remaining functions transfer count bytes, shorts, or longs using
programmed I/O between a memory address and port. Functions insx copy
values into memory; functions outsx copy values from memory. The count
is in elements, not bytes.
SOURCE
/os/pc/l.s
SEE ALSO
dma(10.2), isaconfig(10.2)
x86 INB(10.2)
