[U-Boot] [PATCH] dm: video: Add basic ANSI escape sequence support

[Rob Clark]

On Mon, Sep 11, 2017 at 7:50 AM, Lothar Waßmann <LW at karo-electronics.de> wrote:
> Hi,
>
> On Mon, 11 Sep 2017 05:42:01 -0400 Rob Clark wrote:
>> On Mon, Sep 11, 2017 at 2:18 AM, Simon Glass <sjg at chromium.org> wrote:
>> > On 7 September 2017 at 14:28, Rob Clark <robdclark at gmail.com> wrote:
>> >> Really just the subset that is needed by efi_console.  Perhaps more will
>> >> be added later, for example color support would be useful to implement
>> >> efi_cout_set_attribute().
>> >>
>> >> Signed-off-by: Rob Clark <robdclark at gmail.com>
>> >> ---
>> >>  drivers/video/vidconsole-uclass.c | 112 ++++++++++++++++++++++++++++++++++++++
>> >>  drivers/video/video-uclass.c      |   4 +-
>> >>  include/video.h                   |   7 +++
>> >>  include/video_console.h           |  11 ++++
>> >>  4 files changed, 131 insertions(+), 3 deletions(-)
>> >>
>> >> diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
>> >> index e081d5a0ee..7998b4cf5f 100644
>> >> --- a/drivers/video/vidconsole-uclass.c
>> >> +++ b/drivers/video/vidconsole-uclass.c
>> >> @@ -9,6 +9,7 @@
>> >>   */
>> >>
>> >>  #include <common.h>
>> >> +#include <linux/ctype.h>
>> >>  #include <dm.h>
>> >>  #include <video.h>
>> >>  #include <video_console.h>
>> >> @@ -107,12 +108,123 @@ static void vidconsole_newline(struct udevice *dev)
>> >>         video_sync(dev->parent);
>> >>  }
>> >>
>> >> +/*
>> >> + * Parse a number from string that ends in a non-numeric character..
>> >> + * sscanf() would be nice.  This is just enough for parsing ANSI escape
>> >> + * sequences.
>> >> + */
>> >> +static char *parsenum(char *s, int *num)
>> >
>> > Can you use simple_strtoul() or similar?
>>
>> Possibly, but I'm not sure it is a good idea.. I don't think escape
>> sequences are meant to be encoded with hex or octal number strings.
>> From a quick look, I don't see any escape code terminated with 'x', so
>> maybe it would end up working ok.. but something like ESC[0x1234m
>> should be an escape sequence terminated with x followed by normal
>> chars 1234m and strtoul would get that wrong..
>>
> stroul(s, NULL, 10) will only parse decimal numbers and stop at
> non-decimal digits.
>

And you'd expect simple_strtoul() would too.. but that does not appear
to be the case.  Not sure if that is intentional.

BR,
-R