From f273c77790c813f404641cc704a76c2c23fd87cf Mon Sep 17 00:00:00 2001
From: okuji <okuji@localhost>
Date: Fri, 5 Nov 1999 13:22:07 +0000
Subject: [PATCH] update multiboot.texi.

---
 ChangeLog           |  6 +++++
 docs/multiboot.texi | 57 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index feb66434e..a421e2aef 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+1999-11-05  OKUJI Yoshinori  <okuji@kuicr.kyoto-u.ac.jp>
+
+	* docs/multiboot.texi (Boot information format): Add the members
+	`drives_addr' and `drives_count' into the Multiboot information
+	structure, and added the descriptions.
+	
 1999-11-03  Gordon Matzigkeit  <gord@fig.org>
 
 	* util/mbchk.c (main): Move the version number inside the
diff --git a/docs/multiboot.texi b/docs/multiboot.texi
index 2a4af78a7..d9b229f39 100644
--- a/docs/multiboot.texi
+++ b/docs/multiboot.texi
@@ -540,6 +540,9 @@ follows:
 44      | mmap_length       |    (present if flags[6] is set)
 48      | mmap_addr         |    (present if flags[6] is set)
         +-------------------+
+52      | drives_count      |    (present if flags[7] is set)
+56      | drives_addr       |    (present if flags[7] is set)
+        +-------------------+
 @end group
 @end example
 
@@ -725,6 +728,60 @@ indicated a reserved area.
 The map provided is guaranteed to list all standard @sc{ram} that should
 be available for normal use.
 
+If bit 7 in the @samp{flags} is set, then the @samp{drives_*} fields
+are valid, and indicate the address of the physical address of the first
+drive structure and the number of drive structures. @samp{drives_addr}
+is the address, and @samp{drives_count} is the
+number. @samp{drives_count} may be zero. Each drive structure is
+formatted as follows:
+
+@example
+@group
+        +-------------------+
+0       | drive_number      |
+        +-------------------+
+1       | drive_mode        |
+        +-------------------+
+2       | drive_cylinders   |
+4       | drive_heads       |
+5       | drive_sectors     |
+        +-------------------+
+6       | drive_ports       |
+        +-------------------+
+10      | reserved (0)      |
+        +-------------------+
+@end group
+@end example
+
+The @samp{drive_number} field contains the BIOS drive number. The
+@samp{drive_mode} field represents the access mode used by the boot
+loader. Currently, the following modes are defined:
+
+@table @samp
+@item 0
+CHS mode (traditional cylinder/head/sector addressing mode).
+
+@item 1
+LBA mode (Logical Block Addressing mode).
+@end table
+
+The three fields, @samp{drive_cylinders}, @samp{drive_heads} and
+@samp{drive_sectors}, indicate the geometry of the drive detected by the
+@sc{bios}. @samp{drive_cylinders} contains the number of the
+cylinders. @samp{drive_heads} contains the number of the
+heads. @samp{drive_sectors} contains the number of the sectors per
+track.
+
+The @samp{drive_ports} field contains the physical address of the array
+of the I/O ports used for the drive in the @sc{bios} code. The array
+consists of zero or more unsigned two-bytes integers, and is terminated
+with zero. Note that the array may contain any number of I/O ports that
+are not related to the drive actually (such as @sc{dma} controller's
+ports).
+
+The last field @samp{reserved} is reserved for future use, and must be
+zero. The size is four bytes.
+
 
 @node Examples
 @chapter Examples