Re: [PATCH 1/2] efi: Add efitextmode command for getting/setting the text mode resolution

[Glenn Washburn]

Hi Paul,

On Thu, 12 May 2022 08:10:56 +0200
Paul Menzel <pmenzel@molgen.mpg.de> wrote:

> Dear Glenn,
> 
> 
> Thank you for the patch.
> 
> Am 12.05.22 um 05:07 schrieb Glenn Washburn:
> > This command is meant to behave similarly to the 'mode' command of the EFI
> > Shell application. One difference is that to set the mode the mode number
> > is given, not the rows and columns of the desired mode. Also supported are
> > the arguments "min" and "max", which set the mode to the minimum and
> > maximum mode respectively as calculated by the columns * rows of that mode.
> 
> Did you test this also with QEMU and OVMF?

Yes, although with QEMU with -nographic and the output going through
serial, though not using GRUB's serial terminal. So its still using the
efi console. Is there a reason you're asking? Something not working as
expected?

Glenn

> 
> 
> Kind regards,
> 
> Paul
> 
> 
> > Signed-off-by: Glenn Washburn <development@efficientek.com>
> > ---
> >   grub-core/Makefile.core.def          |   6 ++
> >   grub-core/commands/efi/efitextmode.c | 118 +++++++++++++++++++++++++++
> >   2 files changed, 124 insertions(+)
> >   create mode 100644 grub-core/commands/efi/efitextmode.c
> > 
> > diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> > index 726f51be7..b22e48f0f 100644
> > --- a/grub-core/Makefile.core.def
> > +++ b/grub-core/Makefile.core.def
> > @@ -813,6 +813,12 @@ module = {
> >     enable = efi;
> >   };
> >   
> > +module = {
> > +  name = efitextmode;
> > +  efi = commands/efi/efitextmode.c;
> > +  enable = efi;
> > +};
> > +
> >   module = {
> >     name = blocklist;
> >     common = commands/blocklist.c;
> > diff --git a/grub-core/commands/efi/efitextmode.c 
> > b/grub-core/commands/efi/efitextmode.c
> > new file mode 100644
> > index 000000000..fb72aa6f3
> > --- /dev/null
> > +++ b/grub-core/commands/efi/efitextmode.c
> > @@ -0,0 +1,118 @@
> > +/* efitextmode.c - command to get/set text mode resolution */
> > +/*
> > + *  GRUB  --  GRand Unified Bootloader
> > + *  Copyright (C) 2003,2005,2006,2007,2009  Free Software Foundation, Inc.
> > + *
> > + *  GRUB is free software: you can redistribute it and/or modify
> > + *  it under the terms of the GNU General Public License as published by
> > + *  the Free Software Foundation, either version 3 of the License, or
> > + *  (at your option) any later version.
> > + *
> > + *  GRUB is distributed in the hope that it will be useful,
> > + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + *  GNU General Public License for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > + *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include <grub/dl.h>
> > +#include <grub/misc.h>
> > +#include <grub/mm.h>
> > +#include <grub/command.h>
> > +#include <grub/i18n.h>
> > +#include <grub/efi/efi.h>
> > +#include <grub/efi/api.h>
> > +
> > +GRUB_MOD_LICENSE ("GPLv3+");
> > +
> > +static grub_err_t
> > +grub_cmd_efitextmode (grub_command_t cmd __attribute__ ((unused)),
> > +                 int argc, char **args)
> > +{
> > +  grub_efi_simple_text_output_interface_t *o;
> > +  unsigned long mode;
> > +  const char *p = NULL;
> > +  grub_efi_status_t status;
> > +  grub_efi_uintn_t columns, rows;
> > +  grub_efi_int32_t i;
> > +
> > +  if (argc > 1)
> > +    return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("at most one argument 
> > expected"));
> > +
> > +  o = grub_efi_system_table->con_out;
> > +
> > +  if (argc == 1)
> > +    {
> > +      if (grub_strcmp (args[0], "min") == 0)
> > +   mode = 0;
> > +      else if (grub_strcmp (args[0], "max") == 0)
> > +   mode = o->mode->max_mode - 1;
> > +      else
> > +   {
> > +     mode = grub_strtoul (args[0], &p, 0);
> > +
> > +     if (grub_errno != GRUB_ERR_NONE)
> > +       return grub_errno;
> > +
> > +     if (*args[0] == '\0' || *p != '\0')
> > +       return grub_error (GRUB_ERR_BAD_ARGUMENT,
> > +                          N_("non-numeric or invalid mode `%s'"),
> > +                          args[0]);
> > +   }
> > +
> > +      if (mode < (unsigned long) o->mode->max_mode)
> > +   {
> > +     if (mode != (unsigned long) o->mode->mode)
> > +       {
> > +         status = efi_call_2 (o->set_mode, o, (grub_efi_int32_t) mode);
> > +         if (status == GRUB_EFI_SUCCESS)
> > +           ;
> > +         else if (status == GRUB_EFI_DEVICE_ERROR)
> > +           return grub_error (GRUB_ERR_BAD_DEVICE,
> > +                              N_("device error: could not set requested"
> > +                                 " mode"));
> > +         else if (status == GRUB_EFI_UNSUPPORTED)
> > +           return grub_error (GRUB_ERR_OUT_OF_RANGE,
> > +                              N_("invalid mode: number not valid"));
> > +         else
> > +           return grub_error (GRUB_ERR_BAD_OS,
> > +                              N_("unexpected EFI error number: `%u'"),
> > +                              (unsigned) status);
> > +       }
> > +   }
> > +      else
> > +   return grub_error (GRUB_ERR_BAD_ARGUMENT,
> > +                      N_("invalid mode: `%lu' is greater than maximum"
> > +                         " mode `%lu'"),
> > +                      mode, (unsigned long) o->mode->max_mode);
> > +    }
> > +
> > +  if (argc == 0)
> > +    {
> > +      grub_printf_ (N_("Available modes for console output device.\n"));
> > +
> > +      for (i=0; i < o->mode->max_mode; i++)
> > +   if (GRUB_EFI_SUCCESS == efi_call_4 (o->query_mode, o, i,
> > +                                       &columns, &rows))
> > +     grub_printf_ (N_(" [%lu]  Col %5u Row %5u %c\n"),
> > +                   (unsigned long) i, (unsigned) columns, (unsigned) rows,
> > +                   (i == o->mode->mode) ? '*' : ' ');
> > +    }
> > +
> > +  return GRUB_ERR_NONE;
> > +}
> > +
> > +static grub_command_t cmd;
> > +
> > +GRUB_MOD_INIT(cmp)
> > +{
> > +  cmd = grub_register_command ("efitextmode", grub_cmd_efitextmode,
> > +                          N_("[min|max|mode_num]"), N_("Get or set EFI 
> > text mode."));
> > +}
> > +
> > +GRUB_MOD_FINI(cmp)
> > +{
> > +  grub_unregister_command (cmd);
> > +}