On Sun, 30 Jun 2024 at 13:56, Aditya Garg <gargaditya08@xxxxxxxx> wrote: > > > > > On 30 Jun 2024, at 4:59 PM, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > > > Hello Aditya, Lukas, > > > >> On Sun, 30 Jun 2024 at 10:04, Lukas Wunner <lukas@xxxxxxxxx> wrote: > >> > >>> On Sun, Jun 30, 2024 at 04:42:55AM +0000, Aditya Garg wrote: > >>> Commit 0c18184de990 brought support for T2 Macs in apple-gmux. But in order to > >> > >> Please run patches through scripts/checkpatch.pl before submission. > >> The subject of the commit is missing here and lines should be wrapped > >> at 72 or at least 74 chars. > >> > >> > >>> Based on this patch for GRUB by Andreas Heider <andreas@xxxxxxxxx>: > >>> https://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html > >> > >> Please include his Signed-off-by and cc him. > >> > >> > > > > No. You cannot simply add a signed-off-by on someone else's behalf, > > even if you cc the person. > > > > Andreas contributed code to GRUB (which is a GPLv3 project), and had > > no involvement whatsoever in creating this patch. > > > > A signed-off-by is a statement on the part of the contributor (which > > may or may not be the author) that the contribution in question > > complies with the requirements imposed by the project in terms of > > copyright and licensing. Linux is GPLv2 not v3, so this code should at > > least be dual licensed in order to be reused directly. > > > > I did not look at the GRUB patch, and IANAL, but this code invokes an > > Apple provided protocol (which is proprietary) in a hardcoded way for > > interoperability purposes, and so there is not much to > > copyright/license anyway. I would be fine with having just your > > signoff on this patch, but you could ask Andreas for a GPLv2+3 version > > of his GRUB patch if you are not sure. > > > > I believe this should be GPL2 compatible since it's simple reverse engineered Apple stuff and there are many kernel drivers with apple specific stuff. > > >>> --- a/Documentation/admin-guide/kernel-parameters.txt > >>> +++ b/Documentation/admin-guide/kernel-parameters.txt > >>> @@ -399,6 +399,8 @@ > >>> useful so that a dump capture kernel won't be > >>> shot down by NMI > >>> > >>> + apple_set_os [KNL] Report that macOS is being booted to the firmware > >>> + > >> > >> Why the kernel parameter? Why not do this unconditionally? > >> > >> > > > > Agree that this is suboptimal. If we need a command line param for > > this, please make add it to the efi= list > > I'll leave this to you. If you are fine with a parameter, I'll add it. If you have to be enforced by default, I'm fine with that. > > Or, maybe we add add a parameter that disables this so that in case things break, we can atleast get it done. > > >>> +struct apple_set_os_protocol { > > > > This should be a union not a struct > > > >>> + u64 version; > > > > This should be unsigned long > > > >>> + efi_status_t (__efiapi *set_os_version) (const char *); > >>> + efi_status_t (__efiapi *set_os_vendor) (const char *); > >>> + struct { > >>> + u32 version; > > > > ... to match the mixed_mode overlay which is u32. Alternatively, they > > could both be u64 but the current arrangement is definitely incorrect. > > > >>> + u32 set_os_version; > >>> + u32 set_os_vendor; > >>> + } mixed_mode; > >>> +}; > >> > >> How about declaring this __packed, just to be on the safe side? > >> > > > > I don't think that is necessary. If the mixed_mode overlay is never > > used, it doesn't really matter and you can use unsigned long vs u32, > > in which case all struct members are native word size so there is no > > padding issue. > > > >> Why "mixed_mode"? Seems like an odd name given "mixed mode" > >> in EFI context usually means 64-bit OS, but 32-bit EFI. > >> > > > > This is how the x86 plumbing works for mixed mode. Every EFI protocol > > is a union, with a mixed_mode member describing the 32-bit view. The > > accessor macros (efi_bs_call, efi_table_attr) automatically do the > > right thing depending on the bitness of the firmware. > > > > This means, though, that even protocols that are known not to exist on > > 32-bit firmware need to be implemented in the same way, or the code > > will not build. > > > So should I keep mixed mode or not? Yes. To summarize: - keep your signoff as-is - drop the command line param and handling - make the outer protocol struct a union - use 'unsigned long' for the version field - keep the mixed_mode inner struct - reorganize the conditional in setup_quirks() so that there are two nested if blocks, where the memcmp() appears in the outer if() and apple_set_os() is only called on Apple hardware
