About text mode on EFI when booting Linux

[Dennis Chen <dennis.chen@arm.com>]

Hi Vladimir,

We encounter an error message "no suitable video mode found" when
booting a VM on i386 platform. Though I think this is not a big problem,
but the LinuxKit guys(we use grub2 in LinuxKit project) have some
concerns about this error message, so I submit a patch[1] try to
eliminate this message. Would you please take a look at that patch?

I also dig into the commit logs of the grub2 git tree, and found below
commit:

commit b1257f653367e8d21b625276f53f086d68fab0b3
Author: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date:   Tue Aug 16 16:11:10 2011 +0200

        Don't accept text modes on EFI when booting Linux.
    
        * grub-core/loader/i386/linux.c (ACCEPTS_PURE_TEXT): New define.
        (grub_linux_boot) [!ACCEPTS_PURE_TEXT]: Restrict to graphics modes. 

...
diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c
index 9e3d482..5356d7a 100644
--- a/grub-core/loader/i386/linux.c
+++ b/grub-core/loader/i386/linux.c
@@ -45,15 +45,18 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #include <grub/efi/efi.h>
 #define HAS_VGA_TEXT 0
 #define DEFAULT_VIDEO_MODE "auto"
+#define ACCEPTS_PURE_TEXT 0
 #elif defined (GRUB_MACHINE_IEEE1275)
 #include <grub/ieee1275/ieee1275.h>
 #define HAS_VGA_TEXT 0

I am very curious about the context/background of this commit here, what's
the reason leads us not to accept a text modes on EFI when booting Linux?

[1] https://lists.gnu.org/archive/html/grub-devel/2017-10/msg00031.html

Thanks,
Dennis