From eeaef5e4305497537bd47308724de39c7d6cbf19 Mon Sep 17 00:00:00 2001 From: Steven Stallion Date: Mon, 10 Jun 2013 01:00:09 -0700 Subject: cmd_bootm: Add command line arguments to Plan 9 This patch introduces support for command line arguments to Plan 9. Plan 9 generally dedicates a small region of kernel memory (known as CONFADDR) for runtime configuration. A new environment variable named confaddr was introduced to indicate this location when copying arguments. Signed-off-by: Steven Stallion [trini: Adapt for Simon's changes about correcting argc, no need to bump by 2 now] Signed-off-by: Tom Rini --- doc/README.plan9 | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 doc/README.plan9 (limited to 'doc') diff --git a/doc/README.plan9 b/doc/README.plan9 new file mode 100644 index 0000000000..2d3d0e0cf6 --- /dev/null +++ b/doc/README.plan9 @@ -0,0 +1,18 @@ +Plan 9 from Bell Labs kernel images require additional setup to pass +configuration information to the kernel. An environment variable named +confaddr must be defined with the same value as CONFADDR (see mem.h). +Use of this facility is optional, but should be preferable to manual +configuration. + +When booting an image, arguments supplied to the bootm command will be +copied to CONFADDR. If no arguments are specified, the contents of the +bootargs environment variable will be copied. + +If no command line arguments or bootargs are defined, CONFADDR is left +uninitialized to permit manual configuration. For example, PC-style +configuration could be simulated by issuing a fatload in bootcmd: + + # setenv bootcmd fatload mmc 0 $confaddr plan9.ini; ...; bootm + +Steven Stallion +June 2013 -- cgit v1.2.1