NAME

inb, ins, inl, outb, outs, outl, insb, inss, insl, outsb, outss, outsl − programmed I/O

SYNOPSIS

intinb(int port);

ushortins(int port);

ulonginl(int port);

voidoutb(int port, int value);

voidouts(int port, ushort value);

voidoutl(int port, ulong value);

voidinsb(int port, void *address, int count);

voidinss(int port, void *address, int count);

voidinsl(int port, void *address, int count);

voidoutsb(int port, void *address, int count);

voidoutss(int port, void *address, int count);

voidoutsl(int port, void *address, int count);

DESCRIPTION

The x86 implementation of Inferno 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, Inferno provides similar functions to access devices with an I/O space interface, even though 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)