[U-Boot] [PATCH v2 2/3] Allow displaying the U-Boot banner on a video display

[Bin Meng]

Hi Simon,

On Fri, Jun 16, 2017 at 12:09 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 12 June 2017 at 19:10, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Simon,
>>
>> On Mon, Jun 12, 2017 at 11:17 PM, Simon Glass <sjg at chromium.org> wrote:
>>> Hi Bin,
>>>
>>> On 12 June 2017 at 09:13, Bin Meng <bmeng.cn at gmail.com> wrote:
>>>> Hi Simon,
>>>>
>>>> On Sun, Jun 11, 2017 at 1:59 AM, Simon Glass <sjg at chromium.org> wrote:
>>>>> At present the U-Boot banner is only displayed on the serial console. If
>>>>> this is not visible to the user, the banner does not show. Some devices
>>>>> have a video display which can usefully display this information.
>>>>>
>>>>> Add a banner which is printed after relocation only on non-serial devices
>>>>> if CONFIG_DISPLAY_BOARDINFO_LATE is defined.
>>>>>
>>>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>>>> ---
>>>>>
>>>>> Changes in v2:
>>>>> - Reword function comment for console_announce_r() slighty
>>>>>
>>>>>  common/board_r.c  |  1 +
>>>>>  common/console.c  | 15 +++++++++++----
>>>>>  include/console.h | 12 ++++++++++++
>>>>>  3 files changed, 24 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/common/board_r.c b/common/board_r.c
>>>>> index 15977e4bca..ff11eba5d3 100644
>>>>> --- a/common/board_r.c
>>>>> +++ b/common/board_r.c
>>>>> @@ -846,6 +846,7 @@ static init_fnc_t init_sequence_r[] = {
>>>>>  #endif
>>>>>         console_init_r,         /* fully init console as a device */
>>>>>  #ifdef CONFIG_DISPLAY_BOARDINFO_LATE
>>>>> +       console_announce_r,
>>>>>         show_board_info,
>>>>>  #endif
>>>>>  #ifdef CONFIG_ARCH_MISC_INIT
>>>>> diff --git a/common/console.c b/common/console.c
>>>>> index 1232808df5..3fcd7ce66b 100644
>>>>> --- a/common/console.c
>>>>> +++ b/common/console.c
>>>>> @@ -202,7 +202,6 @@ static void console_putc(int file, const char c)
>>>>>         }
>>>>>  }
>>>>>
>>>>> -#if CONFIG_IS_ENABLED(PRE_CONSOLE_BUFFER)
>>>>
>>>> Why removing this? Without PRE_CONSOLE_BUFFER, I doubt it works.
>>>
>>> I want to be able to call the function below. It seems to work OK and
>>> it doesn't rely on that option.
>>>
>>
>> See comments below.
>>
>>>>
>>>>>  static void console_puts_noserial(int file, const char *s)
>>>>>  {
>>>>>         int i;
>>>>> @@ -214,7 +213,6 @@ static void console_puts_noserial(int file, const char *s)
>>>>>                         dev->puts(dev, s);
>>>>>         }
>>>>>  }
>>>>> -#endif
>>>>>
>>>>>  static void console_puts(int file, const char *s)
>>>>>  {
>>>>> @@ -248,13 +246,11 @@ static inline void console_putc(int file, const char c)
>>>>>         stdio_devices[file]->putc(stdio_devices[file], c);
>>>>>  }
>>>>>
>>>>> -#if CONFIG_IS_ENABLED(PRE_CONSOLE_BUFFER)
>>>>>  static inline void console_puts_noserial(int file, const char *s)
>>>>>  {
>>>>>         if (strcmp(stdio_devices[file]->name, "serial") != 0)
>>>>>                 stdio_devices[file]->puts(stdio_devices[file], s);
>>>>>  }
>>>>> -#endif
>>>>>
>>>>>  static inline void console_puts(int file, const char *s)
>>>>>  {
>>>>> @@ -699,6 +695,17 @@ static void console_update_silent(void)
>>>>>  #endif
>>>>>  }
>>>>>
>>>>> +int console_announce_r(void)
>>>>> +{
>>>>> +       char buf[DISPLAY_OPTIONS_BANNER_LENGTH];
>>>>> +
>>>>> +       display_options_get_banner(false, buf, sizeof(buf));
>>>>> +
>>>>> +       console_puts_noserial(stdout, buf);
>>
>> Then I think we should do something like this:
>>
>> int console_announce_r(void)
>> {
>> #ifndef CONFIG_PRE_CONSOLE_BUFFER
>>         char buf[DISPLAY_OPTIONS_BANNER_LENGTH];
>>
>>         display_options_get_banner(false, buf, sizeof(buf));
>>         console_puts_noserial(stdout, buf);
>> #endif
>> }
>>
>> If we don't do this, there will be duplicated U-Boot version string
>> shown on the screen if CONFIG_PRE_CONSOLE_BUFFER is defined.
>
> I don't think so. This is a different thing. The pre-console buffer
> only exists until console_init_f(), i.e. very early in pre-relocation
> U-Boot. When console_init_f() is called the buffer is printed to the
> (serial) console.
>

But in fact, the version string will be printed twice on the screen
(not on the serial) if CONFIG_PRE_CONSOLE_BUFFER is defined. One
existed in the pre-console buffer, as you mentioned. The other one is
what you added here.

> My patch is all about what happens after relocation. By this time the
> pre-console buffer has been sent to the serial port. I want to display
> the version number on the screen, and this should not affect the
> pre-console buffer in any way.
>

[snip]

Regards,
Bin