[PATCH v5 05/28] efi: serial: Support arrow keys

[Simon Glass]

Hi Heinrich,

On Fri, 17 Dec 2021 at 10:14, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 12/17/21 17:37, Simon Glass wrote:
> > Hi Heinrich,
> >
> > On Thu, 9 Dec 2021 at 12:44, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
> >>
> >> On 12/4/21 07:56, Simon Glass wrote:
> >>> At present only the backspace key is supported in U-Boot, when running as
> >>> an EFI app. Add support for arrows, home and end as well, to make the CLI
> >>> more friendly.
> >>>
> >>> Signed-off-by: Simon Glass <sjg at chromium.org>
> >>> ---
> >>>
> >>> (no changes since v1)
> >>>
> >>>    drivers/serial/serial_efi.c | 11 +++++++++--
> >>>    1 file changed, 9 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/drivers/serial/serial_efi.c b/drivers/serial/serial_efi.c
> >>> index 33ddbd6080c..0067576389d 100644
> >>> --- a/drivers/serial/serial_efi.c
> >>> +++ b/drivers/serial/serial_efi.c
> >>> @@ -24,6 +24,9 @@ struct serial_efi_priv {
> >>>        bool have_key;
> >>>    };
> >>>
> >>> +/* Convert a lower-case character to its ctrl-char equivalent */
> >>> +#define CTL_CH(c)            ((c) - 'a' + 1)
> >>> +
> >>>    int serial_efi_setbrg(struct udevice *dev, int baudrate)
> >>>    {
> >>>        return 0;
> >>> @@ -49,6 +52,7 @@ static int serial_efi_get_key(struct serial_efi_priv *priv)
> >>>    static int serial_efi_getc(struct udevice *dev)
> >>>    {
> >>>        struct serial_efi_priv *priv = dev_get_priv(dev);
> >>> +     char conv_scan[10] = {0, 'p', 'n', 'f', 'b', 'a', 'e', 0, 8};
> >>>        int ret, ch;
> >>>
> >>>        ret = serial_efi_get_key(priv);
> >>> @@ -63,8 +67,11 @@ static int serial_efi_getc(struct udevice *dev)
> >>>         * key scan code of 8. Handle this so that backspace works correctly
> >>>         * in the U-Boot command line.
> >>>         */
> >>> -     if (!ch && priv->key.scan_code == 8)
> >>> -             ch = 8;
> >>> +     if (!ch && priv->key.scan_code < sizeof(conv_scan)) {
> >>> +             ch = conv_scan[priv->key.scan_code];
> >>> +             if (ch >= 'a')
> >>> +                     ch -= 'a' - 1;
> >>
> >> This is not what a serial console would use in Linux. Just try U-Boot's
> >> conitrace command. If you use the following, we get compatibility with
> >> the rest of U-Boot:
> >>
> >> 1b 5b 32 7e - insert
> >> 1b 5b 33 7e - delete
> >> 1b 5b 35 7e - page up
> >> 1b 5b 36 7e - page down
> >> 1b 5b 41 - up
> >> 1b 5b 42 - down
> >> 1b 5b 43 - right
> >> 1b 5b 44 - left
> >> 1b 5b 46 - end
> >> 1b 5b 48 - home
> >
> > That's more complicated since it requires the serial driver to convert
> > one character into multiple. We can always add it later if needed. But
> > this does command-line history, etc. working in the app.
>
> Yes you will need a ring buffer as in the USB keyboard driver.
>
> lib/efi_loader/efi_console.c only understands the multi-byte sequences.
> I do not know if there are other places which have the same limitation.

The ones I am using here are the official U-Boot codes. Perhaps
EFI_LOADER should be fixed, but this doesn't matter for the EFI app.

In any case, this work can be done later if needed.

Regards,
Simon