On Thu, Apr 12, 2018 at 07:09:58PM +0200, Lukasz Zemczak wrote: > Hello everyone, > > I'm writing to this list since I would like to get some feedback on an > additional option to the grub-install tool we would find very > convenient to have. The diff is attached to the e-mail (also available > as a pastebin [1]). > > The idea of the --auto-nvram (the name is just a proposition) flag is > a bit similar to what --no-nvram does. After providing the option > during grub-install, the tool will attempt to guess if there is access > to NVRAM variables for EFI and/or IEEE1275 and, if yes, perform the > usual variable updates. If no access to the NVRAM is available the > whole thing is handled somewhat similar to --no-nvram + a warning
Make sense for me but I am not sure about "a warning". Hmmm... Is it really needed? > message displayed. Rationale: > > We would like to use this in Ubuntu for cases of dual BIOS/EFI > bootloaders installed (at the same time), helpful for the situation of > calling grub-install --target=x86_64-efi from the shim-efi package on > a BIOS legacy-mode booted machine. For this legacy-mode case when > running on a EFI-enabled device, currently this causes grub-install to > fail as obviously there is no access to the NVRAM and no --no-nvram is > given. We don't want to unconditionally append --no-nvram as this is > not what we want to happen for the case of a system that is actually > booted in EFI-mode. With this flag, we would be simply performing a > grub-install --target=x86_64-efi --auto-nvram unconditionally which > would do the right thing in both cases, allowing for a much simpler > handling of this dual-bootloader case in Ubuntu. Having it being done > inside grub-installer makes everything much cleaner. > > This is of course just a proposition about which I wanted to get some > feedback from people that know the codebase the most. It's my first > time working on the grub project so apologies for any flukes or > silliness in the code or the idea itself. > > Thank you! > > Best regards, > > [1] http://paste.ubuntu.com/p/cWR3k3NZgF/ Next time please use git format-patch/send-email to send the patches. > diff --git a/grub-core/osdep/basic/no_platform.c > b/grub-core/osdep/basic/no_platform.c > index d76c34c14..b39e97f48 100644 > --- a/grub-core/osdep/basic/no_platform.c > +++ b/grub-core/osdep/basic/no_platform.c > @@ -25,7 +25,7 @@ > > void > grub_install_register_ieee1275 (int is_prep, const char *install_device, > - int partno, const char *relpath) > + int partno, const char *relpath, int > detect_nvram) > { > grub_util_error ("%s", _("no IEEE1275 routines are available for your > platform")); > } > @@ -33,7 +33,8 @@ grub_install_register_ieee1275 (int is_prep, const char > *install_device, > void > grub_install_register_efi (grub_device_t efidir_grub_dev, > const char *efifile_path, > - const char *efi_distributor) > + const char *efi_distributor, > + int detect_nvram) > { > grub_util_error ("%s", _("no EFI routines are available for your > platform")); > } > diff --git a/grub-core/osdep/unix/platform.c b/grub-core/osdep/unix/platform.c > index ca448bc11..4eb2c11c9 100644 > --- a/grub-core/osdep/unix/platform.c > +++ b/grub-core/osdep/unix/platform.c > @@ -134,7 +134,8 @@ grub_install_remove_efi_entries_by_distributor (const > char *efi_distributor) > int > grub_install_register_efi (grub_device_t efidir_grub_dev, > const char *efifile_path, > - const char *efi_distributor) > + const char *efi_distributor, > + int detect_nvram) > { > const char * efidir_disk; > int efidir_part; > @@ -153,6 +154,21 @@ grub_install_register_efi (grub_device_t efidir_grub_dev, > #ifdef __linux__ > grub_util_exec ((const char * []){ "modprobe", "-q", "efivars", NULL }); > #endif > + > + /* If requested, we try to detect if NVRAM access is available and if not, > + warn the user and resume normal operation. */ > + if (detect_nvram) > + { > + error = grub_util_exec_redirect_null ((const char * []){ "efibootmgr", > NULL }); > + if (error == 2) > + { > + grub_util_warn ("%s", _("Auto-NVRAM selected and no EFI variable > support detected on the system.")); Wait, I have a feeling that you should fail hard here. In general I think that if somebody passed --auto-nvram on platforms with NVRAM and something fails then everything should fail. If somebody passed --auto-nvram on platforms without NVRAM then any attempt to access NVRAM should be skipped (silently?). Does it make sense? Daniel _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
