[PATCH] Documentation: admin-guide: add earlycon documentation for RISC-V

Paul Walmsley
2019-10-09T19:53:53Z

Kernels booting on RISC-V can specify "earlycon" with no options on
the Linux command line, and the generic DT earlycon support will query
the "chosen/stdout-path" property (if present) to determine which
early console device to use. Document this appropriately in the
admin-guide.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andreas Schwab <schwab@suse.de>
---
Documentation/admin-guide/kernel-parameters.txt | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index c7ac2f3ac99f..011fee969ece 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -990,6 +990,10 @@
[X86] When used with no options the early console is
determined by the ACPI SPCR table.

+ [RISCV] When used with no options, the early
+ console is determined by the stdout-path
+ property in the device tree's chosen node.
+
cdns,<addr>[,options]
Start an early, polled-mode console on a Cadence
(xuartps) serial port at the specified address. Only
--
2.23.0