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authorSteven Stallion <sstallion@gmail.com>2013-06-10 01:00:09 -0700
committerTom Rini <trini@ti.com>2013-06-26 10:25:22 -0400
commiteeaef5e4305497537bd47308724de39c7d6cbf19 (patch)
tree213aef8f7119b74b9bbf7c4c9a1e0812c6ac26c9 /doc
parent041bca5ba3adb48750d0a438cb3b1356a0c2e603 (diff)
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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 <sstallion@gmail.com> [trini: Adapt for Simon's changes about correcting argc, no need to bump by 2 now] Signed-off-by: Tom Rini <trini@ti.com>
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diff --git a/doc/README.plan9 b/doc/README.plan9
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+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