Re: [PATCH] sh-sci: Extend sh-sci driver with early console V2

[Magnus Damm <magnus.damm@gmail.com>]

Hey Kawasaki-san,

2010/4/11 Shin-ichiro KAWASAKI <kawasaki@juno.dti.ne.jp>:
> Hello Magnus,
>
> I'm in trouble with qemu-sh serial console.  Don't you have any
> guide on this trouble?

Yes, I think the defconfig is missing one thing. Please try setting
CONFIG_SERIAL_SH_SCI_NR_UARTS=2. See below.

> With the patch, qemu-sh serial console doesn't work.
> The emulated device is r2d+.
>
>  - no earlyprintk option
>  ... Qemu carshes with assertion. No kernel boot log printed.
>      I guess it touches sh-sci.0 registers, which qemu doesn't support.

Hm, I'm not sure why this happens. Did you update the kernel command
line to use ttySC1?

This commit in linux-2.6 git may be useful:

 cd5f107628ab89c5dec5ad923f1c27f4cba41972

>  - earlyprintk=sh-sci.1
>  ... Qemu boots up with kernel boot log output,
>      but the log message stops with
>      "turn off boot console early_ttySC0' message.
>      No login prompt appears.
>  - earlyprintk=sh-sci.1,115200,keep
>  ... The message "turn off boots up ..." disappears, but no
>      login prompt appears.

I think this is because CONFIG_SERIAL_SH_SCI_NR_UARTS is set to 1. Or
perhaps is your user space still using ttySC0 instead of ttySC1?

Does updating CONFIG_SERIAL_SH_SCI_NR_UARTS to 2 solve your issue?

Thanks for the report and sorry about the breakage.

/ magnus