ref: 9c6897e848933b1cb256416987c55d0a12f6e3bd
parent: 96eb90fba188f73d2172f8e8de6a96be85b6d823
author: cinap_lenrek <cinap_lenrek@felloff.net>
date: Fri Dec 22 23:45:22 EST 2017
arch(3): document #P/realmodemem file
--- a/sys/man/3/arch
+++ b/sys/man/3/arch
@@ -15,6 +15,7 @@
.B /dev/iow
.B /dev/irqalloc
.B /dev/msr
+.B /dev/realmodemem
.SH DESCRIPTION
This device presents textual information about PC hardware and allows
user-level control of the I/O ports on x86-class machines.
@@ -128,6 +129,12 @@
Reads and writes to
.I msr
go to the P4/P6/Core/Core2/AMD64 MSRs.
+.PP
+The
+.I realmodemem
+file provides access to the first megabyte of memory. This
+allows reading BIOS data structures and option ROMs.
+Writing is limited to the VGA framebuffer at [0xA0000-0xBFFFF].
.PP
Reads and writes to
.I ec