[U-Boot] [PATCH v1 08/12] efi_loader: console support for color attributes

Rob Clark
2017-10-04T23:19:58Z

On Wed, Oct 4, 2017 at 6:01 PM, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
> On 10/04/2017 10:54 PM, Rob Clark wrote:
>> On Wed, Oct 4, 2017 at 2:53 PM, Heinrich Schuchardt <xypron.glpk@gmx.de> wrote:
>>> On 09/10/2017 03:22 PM, Rob Clark wrote:
>>>> Shell.efi uses this, and supporting color attributes makes things look
>>>> nicer. Map the EFI fg/bg color attributes to ANSI escape sequences.
>>>> Not all colors have a perfect match, but spec just says "Devices
>>>> supporting a different number of text colors are required to emulate the
>>>> above colors to the best of the device’s capabilities".
>>>>
>>>> Signed-off-by: Rob Clark <robdclark@gmail.com>
>>>> ---
>>>> include/efi_api.h | 29 +++++++++++++++++++++++++++++
>>>> lib/efi_loader/efi_console.c | 30 ++++++++++++++++++++++++++++++
>>>> 2 files changed, 59 insertions(+)
>>>>
>>>> diff --git a/include/efi_api.h b/include/efi_api.h
>>>> index 87c8ffe68e..3cc1dbac2e 100644
>>>> --- a/include/efi_api.h
>>>> +++ b/include/efi_api.h
>>>> @@ -426,6 +426,35 @@ struct simple_text_output_mode {
>>>> EFI_GUID(0x387477c2, 0x69c7, 0x11d2, \
>>>> 0x8e, 0x39, 0x0, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
>>>>
>>>> +#define EFI_BLACK 0x00
>>>> +#define EFI_BLUE 0x01
>>>> +#define EFI_GREEN 0x02
>>>> +#define EFI_CYAN 0x03
>>>> +#define EFI_RED 0x04
>>>> +#define EFI_MAGENTA 0x05
>>>> +#define EFI_BROWN 0x06
>>>> +#define EFI_LIGHTGRAY 0x07
>>>> +#define EFI_BRIGHT 0x08
>>>> +#define EFI_DARKGRAY 0x08
>>>> +#define EFI_LIGHTBLUE 0x09
>>>> +#define EFI_LIGHTGREEN 0x0a
>>>> +#define EFI_LIGHTCYAN 0x0b
>>>> +#define EFI_LIGHTRED 0x0c
>>>> +#define EFI_LIGHTMAGENTA 0x0d
>>>> +#define EFI_YELLOW 0x0e
>>>> +#define EFI_WHITE 0x0f
>>>> +#define EFI_BACKGROUND_BLACK 0x00
>>>> +#define EFI_BACKGROUND_BLUE 0x10
>>>> +#define EFI_BACKGROUND_GREEN 0x20
>>>> +#define EFI_BACKGROUND_CYAN 0x30
>>>> +#define EFI_BACKGROUND_RED 0x40
>>>> +#define EFI_BACKGROUND_MAGENTA 0x50
>>>> +#define EFI_BACKGROUND_BROWN 0x60
>>>> +#define EFI_BACKGROUND_LIGHTGRAY 0x70
>>>
>>> Will we ever use these constants?
>>>
>>
>> possibly not, but it is useful to understand what is going on with
>> efi->ansi mapping, so I would prefer to keep them.
>>
>>>
>>> Where are the comments explaining the defines below?
>>>
>>>> +
>>>> +#define EFI_ATTR_FG(attr) ((attr) & 0x0f)
>>>
>>> This saves 8 entries in the table below.
>>> +#define EFI_ATTR_FG(attr) ((attr) & 0x07)
>>>
>>>> +#define EFI_ATTR_BG(attr) (((attr) >> 4) & 0x7)
>>>
>>> Add
>>> #define EFI_ATTR_BOLD(attr) (((attr) >> 3) & 0x01)
>>>
>>>> +
>>>> struct efi_simple_text_output_protocol {
>>>> void *reset;
>>>> efi_status_t (EFIAPI *output_string)(
>>>> diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
>>>> index 2e13fdc096..fcd65ca488 100644
>>>> --- a/lib/efi_loader/efi_console.c
>>>> +++ b/lib/efi_loader/efi_console.c
>>>> @@ -316,12 +316,42 @@ static efi_status_t EFIAPI efi_cout_set_mode(
>>>> return EFI_EXIT(EFI_SUCCESS);
>>>> }
>>>>
>>>> +static const struct {
>>>> + unsigned fg;
>>>> + unsigned bg;
>>>> +} color[] = {
>>>> + { 30, 40 }, /* 0: black */
>>>> + { 34, 44 }, /* 1: blue */
>>>> + { 32, 42 }, /* 2: green */
>>>> + { 36, 46 }, /* 3: cyan */
>>>> + { 31, 41 }, /* 4: red */
>>>> + { 35, 45 }, /* 5: magenta */
>>>> + { 30, 40 }, /* 6: brown, map to black */
>>>
>>> This should be { 33, 43 }
>>>
>>>> + { 37, 47 }, /* 7: light grey, map to white */
>>>
>>> The entries below are redundant.
>>>
>>>> + { 37, 47 }, /* 8: bright, map to white */
>>>> + { 34, 44 }, /* 9: light blue, map to blue */
>>>> + { 32, 42 }, /* A: light green, map to green */
>>>> + { 36, 46 }, /* B: light cyan, map to cyan */
>>>> + { 31, 41 }, /* C: light red, map to red */
>>>> + { 35, 45 }, /* D: light magenta, map to magenta */
>>>> + { 33, 43 }, /* E: yellow */
>>>> + { 37, 47 }, /* F: white */
>>>> +};
>>>> +
>>
>> I'm not totally convinced about mapping extra colors that UEFI defines
>> to bold.. unless you have some example of prior-art for this on other
>> platforms.
>
> See
> Standard ECMA-48 - Control Functions for Coded Character Sets
> chapter 8.3.117 SGR - SELECT GRAPHIC RENDITION
>
> 1 - bold or increased intensity
> 22 - normal colour or normal intensity (neither bold nor faint)
>
> You can easily experiment in your bash shell like this:
>
> printf "\x1b[1;32;40m bold \x1b[22;32;40m normal\x1b[22;39;49m\n";
>
> You will find that "bold" prints bold and bright in the KDE konsole and
> xterm.

but I think we don't want (potential) font changes, just color changes..

if you can find the code in edk2 that does this, I guess it would be a
reasonable precedent to follow.. but if not I wanted to avoid things
that might be specific to particular terminal emulators, since I
wasn't really looking forward to testing them all. Otherwise I'd just
rely on the extension that allowed 256 colors..

BR,
-R

> Using colors 90-97 as foreground colors produces only bright but not
> bold in the KDE konsole and xterm:
>
> printf "\x1b[92;40m bold \x1b[32;40m normal\x1b[22;39;49m\n";
>
> But these codes are not defined in ECMA-48.
>
> Best regards
>
> Heinrich
>