Re: [PATCH 12/17] tty: New RISC-V SBI Console Driver
From: Palmer Dabbelt
Date: Fri Jun 23 2017 - 20:45:44 EST
On Wed, 07 Jun 2017 00:58:04 PDT (-0700), Arnd Bergmann wrote:
> On Wed, Jun 7, 2017 at 9:15 AM, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>> CC (hypervisor) console folks
>> On Wed, Jun 7, 2017 at 1:00 AM, Palmer Dabbelt <palmer@xxxxxxxxxxx> wrote:
>>> 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@xxxxxxxxxxx>
>>> 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
>>> +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
>>> + * 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