Re: [PATCH 12/17] tty: New RISC-V SBI Console Driver
From: Arnd Bergmann
Date: Wed Jun 07 2017 - 03:58:10 EST
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
>> 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.
>> + * 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