summaryrefslogtreecommitdiff
path: root/sys/man/3
diff options
context:
space:
mode:
authorcinap_lenrek <cinap_lenrek@felloff.net>2017-12-23 04:45:22 +0100
committercinap_lenrek <cinap_lenrek@felloff.net>2017-12-23 04:45:22 +0100
commit9c6897e848933b1cb256416987c55d0a12f6e3bd (patch)
treeeb21e93ac66779a9ecadef4daaaafc649f6c40e8 /sys/man/3
parent96eb90fba188f73d2172f8e8de6a96be85b6d823 (diff)
arch(3): document #P/realmodemem file
Diffstat (limited to 'sys/man/3')
-rw-r--r--sys/man/3/arch7
1 files changed, 7 insertions, 0 deletions
diff --git a/sys/man/3/arch b/sys/man/3/arch
index fd28462ad..621836353 100644
--- a/sys/man/3/arch
+++ b/sys/man/3/arch
@@ -15,6 +15,7 @@ arch \- architecture-specific information and control
.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.
@@ -129,6 +130,12 @@ 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
transfer bytes from and to the embedded controller.