Dave wrote:
> How does one directly access an I/O address from C?
>
> For example if I want to write a char to port 0x80 (or read a char from a
> port) what is the statement?
Use outb() et al (defined in asm/io.h).
> How about memory mapped I/O? If one wants to directly access a specific
> memory address what are the statements?
Just access the appropriate memory address. However, on PentiumPro and
upwards you may have to take additional steps to force the processor
to execute the memory reads/writes in the correct order.
> Is direct I/O and direct memory access part of ANSI C?
No. I/O is highly platform-specific. The ANSI standard doesn't deal
with any platform-specific issues.
--
Glynn Clements <[EMAIL PROTECTED]>
