Re: [PATCH 12/17] tty: New RISC-V SBI Console Driver

On Wed, Jun 7, 2017 at 9:15 AM, Geert Uytterhoeven [off-list ref] wrote:

CC (hypervisor) console folks

On Wed, Jun 7, 2017 at 1:00 AM, Palmer Dabbelt [off-list ref] wrote:

quoted

This patch adds a new driver for the console availiable via the RISC-V
SBI.  This console is specified to be used for early boot messages, and
is designed to be a very simple (albiet somewhat slow) console that is
always availiable.  All RISC-V systems have an SBI console.

The SBI console is made availiable for early printk messages and is also
availiable as a regular console.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
---
 drivers/tty/hvc/Kconfig   |  11 +++++
 drivers/tty/hvc/Makefile  |   1 +
 drivers/tty/hvc/hvc_sbi.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 114 insertions(+)
 create mode 100644 drivers/tty/hvc/hvc_sbi.c

diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
index 574da15fe618..f3774adab240 100644
--- a/drivers/tty/hvc/Kconfig
+++ b/drivers/tty/hvc/Kconfig

@@ -114,4 +114,15 @@ config HVCS
          which will also be compiled when this driver is built as a
          module.

+config HVC_SBI
+       bool "SBI console support"
+       depends on RISCV
+       select HVC_DRIVER
+       default y
+       help
+         This enables support for console output via RISC-V SBI calls, which
+         is normally used only during boot to output printk.
+
+         If you don't know what do to here, say Y.
+
 endif # TTY

Please move this a little higher along with the other HVC_DRIVER
implementations.

quoted

+ * RISC-V SBI interface to hvc_console.c
+ *  based on drivers-tty/hvc/hvc_udbg.c
+ *
+ * Copyright (C) 2008 David Gibson, IBM Corporation
+ * Copyright (C) 2012 Regents of the University of California

2017?

        Arnd