Module Name: src
Committed By: phx
Date: Tue Apr 19 14:12:54 UTC 2011
Modified Files:
src/sys/arch/sandpoint/stand/altboot: README.altboot
Log Message:
Added a detailed description of altboot command line and boot arguments.
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/sys/arch/sandpoint/stand/altboot/README.altboot
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/sandpoint/stand/altboot/README.altboot
diff -u src/sys/arch/sandpoint/stand/altboot/README.altboot:1.3 src/sys/arch/sandpoint/stand/altboot/README.altboot:1.4
--- src/sys/arch/sandpoint/stand/altboot/README.altboot:1.3 Fri Apr 8 08:29:07 2011
+++ src/sys/arch/sandpoint/stand/altboot/README.altboot Tue Apr 19 14:12:54 2011
@@ -1,6 +1,6 @@
/// notes about altboot ///
-$NetBSD: README.altboot,v 1.3 2011/04/08 08:29:07 phx Exp $
+$NetBSD: README.altboot,v 1.4 2011/04/19 14:12:54 phx Exp $
Altboot is a functional bridge to fill the gap between a NAS product
custom bootloader and the NetBSD kernel startup environment. Altboot
@@ -58,4 +58,47 @@
- product family indication.
- preloaded kernel module names (under development).
+When no arguments are given, altboot defaults to boot a kernel called
+"netbsd" from the root partition of the first disk in multiuser mode.
+
+Boot arguments may be passed in three ways:
+- On the command line, directly after the "go 0x1000000" command.
+- From the U-Boot "bootargs" environment variable, when started by "bootm".
+- By entering the interactive mode.
+
+The following boot arguments are recognized:
+- multi boot into multiuser
+- auto boot into multiuser
+- single boot into singleuser
+- ask ask for boot device
+- ddb drop into the kernel debugger
+- userconf change configured devices
+
+The following boot flags are recognized:
+- norm boot normally
+- quiet boot quietly
+- verb boot verbosely
+- silent boot silently
+- debug boot with debug output
+
+Additionally the special argument "altboot" is recognized, which replaces
+the actually running altboot program with the loaded binary file and
+restarts itself. Mainly useful for altboot testing.
+
+Multiple arguments may be specified at once, although not all combinations
+make sense. The format of an altboot command line is:
+
+ [[<bootargs> ...] <devicename>:[<bootfile>]]
+
+The following device names are supported:
+- tftp boot from TFTP (address retrieved by DHCP)
+- nfs boot from NFS (address retrieved by DHCP)
+- wd[N[P]] boot from disk N, partition P, defaults to wd0a
+- mem boot from memory
+
+For tftp and nfs the bootfile is determined by DHCP, when missing.
+For wd it defaults to "netbsd".
+For mem the bootfile is actually a hexadecimal address to load from and
+is mandatory.
+
### ### ###
