On Sun, Oct 25, 2020 at 6:50 AM Ard Biesheuvel <ard.biesheuvel@xxxxxxx> wrote: > > Recent Linux kernels will invoke the LoadFile2 protocol installed on a > well-known vendor media devicepath to load the initrd if it is exposed > by the firmware. Using this method is preferred for two reasons: > - the Linux kernel is in charge of allocating the memory, and so it can > implement any placement policy it wants (given that these tend to > change between kernel versions), > - it is no longer necessary to modify the device tree provided by the > firmware. > > So let's install this protocol when handling the 'initrd' command if > such a recent kernel was detected (based on the PE/COFF image version), > and defer loading the initrd contents until the point where the kernel > invokes the LoadFile2 protocol. > Thanks for adding the support for LoadFile2 protocol. This was one of the blockers for full RISC-V support. How do you prefer to proceed with RISC-V support ? For RISC-V, we just need to move the arm64 loader to a common file so that both RISC-V/ARM64 can use it apart from few header file fixes. During the last attempt[1], I moved it to loader/efi/linux.c. I am happy to test it on Qemu/hardware, if you want to send the series either part of this one or a separate series. I can rebase my previous series on top of this series as well. Please let me know your preference. [1] https://www.mail-archive.com/grub-devel@xxxxxxx/msg30107.html > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxx> > --- > grub-core/loader/arm64/linux.c | 109 +++++++++++++++++++- > 1 file changed, 108 insertions(+), 1 deletion(-) > > diff --git a/grub-core/loader/arm64/linux.c b/grub-core/loader/arm64/linux.c > index 28ff8584a3b5..c6a95e1f0c43 100644 > --- a/grub-core/loader/arm64/linux.c > +++ b/grub-core/loader/arm64/linux.c > @@ -48,6 +48,10 @@ static grub_uint32_t cmdline_size; > static grub_addr_t initrd_start; > static grub_addr_t initrd_end; > > +static struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; > +static grub_efi_handle_t initrd_lf2_handle; > +static int initrd_use_loadfile2; > + > grub_err_t > grub_arch_efi_linux_load_image_header (grub_file_t file, > struct linux_arch_kernel_header * lh) > @@ -81,6 +85,18 @@ grub_arch_efi_linux_load_image_header (grub_file_t file, > return grub_error(GRUB_ERR_FILE_READ_ERROR, "failed to read COFF image header"); > } > > + /* > + * Linux kernels built for any architecture are guaranteed to support the > + * LoadFile2 based initrd loading protocol if the image version is >= 1. > + */ > + if (lh->coff_image_header.optional_header.major_image_version >= 1) > + initrd_use_loadfile2 = 1; > + else > + initrd_use_loadfile2 = 0; > + > + grub_dprintf ("linux", "LoadFile2 initrd loading %sabled\n", > + initrd_use_loadfile2 ? "en" : "dis"); > + > return GRUB_ERR_NONE; > } > > @@ -250,13 +266,86 @@ allocate_initrd_mem (int initrd_pages) > GRUB_EFI_LOADER_DATA); > } > > +struct initrd_media_device_path { > + grub_efi_vendor_media_device_path_t vendor; > + grub_efi_device_path_t end; > +} GRUB_PACKED; > + > +#define LINUX_EFI_INITRD_MEDIA_GUID \ > + { 0x5568e427, 0x68fc, 0x4f3d, \ > + { 0xac, 0x74, 0xca, 0x55, 0x52, 0x31, 0xcc, 0x68 } \ > + } > + > +static struct initrd_media_device_path initrd_lf2_device_path = { > + { > + { > + GRUB_EFI_MEDIA_DEVICE_PATH_TYPE, > + GRUB_EFI_VENDOR_MEDIA_DEVICE_PATH_SUBTYPE, > + sizeof(grub_efi_vendor_media_device_path_t), > + }, > + LINUX_EFI_INITRD_MEDIA_GUID > + }, { > + GRUB_EFI_END_DEVICE_PATH_TYPE, > + GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE, > + sizeof(grub_efi_device_path_t) > + } > +}; > + > +static grub_efi_status_t initrd_load_file2(grub_efi_load_file2_t *this, > + grub_efi_device_path_t *device_path, > + grub_efi_boolean_t boot_policy, > + grub_efi_uintn_t *buffer_size, > + void *buffer); > + > +static grub_efi_load_file2_t initrd_lf2 = { > + initrd_load_file2 > +}; > + > +static grub_efi_status_t initrd_load_file2(grub_efi_load_file2_t *this, > + grub_efi_device_path_t *device_path, > + grub_efi_boolean_t boot_policy, > + grub_efi_uintn_t *buffer_size, > + void *buffer) > +{ > + grub_efi_status_t status = GRUB_EFI_SUCCESS; > + grub_efi_uintn_t initrd_size; > + > + if (!this || this != &initrd_lf2 || !buffer_size) > + return GRUB_EFI_INVALID_PARAMETER; > + > + if (device_path->type != GRUB_EFI_END_DEVICE_PATH_TYPE || > + device_path->subtype != GRUB_EFI_END_ENTIRE_DEVICE_PATH_SUBTYPE) > + return GRUB_EFI_NOT_FOUND; > + > + if (boot_policy) > + return GRUB_EFI_UNSUPPORTED; > + > + initrd_size = grub_get_initrd_size (&initrd_ctx); > + if (!buffer || *buffer_size < initrd_size) > + { > + *buffer_size = initrd_size; > + return GRUB_EFI_BUFFER_TOO_SMALL; > + } > + > + grub_dprintf ("linux", "Loading initrd via LOAD_FILE2_PROTOCOL\n"); > + > + if (grub_initrd_load (&initrd_ctx, NULL, buffer)) > + status = GRUB_EFI_LOAD_ERROR; > + > + grub_initrd_close (&initrd_ctx); > + return status; > +} > + > static grub_err_t > grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), > int argc, char *argv[]) > { > - struct grub_linux_initrd_context initrd_ctx = { 0, 0, 0 }; > int initrd_size, initrd_pages; > void *initrd_mem = NULL; > + grub_efi_guid_t load_file2_guid = GRUB_EFI_LOAD_FILE2_PROTOCOL_GUID; > + grub_efi_guid_t device_path_guid = GRUB_EFI_DEVICE_PATH_GUID; > + grub_efi_boot_services_t *b; > + grub_efi_status_t status; > > if (argc == 0) > { > @@ -274,6 +363,24 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)), > if (grub_initrd_init (argc, argv, &initrd_ctx)) > goto fail; > > + if (initrd_use_loadfile2) > + { > + b = grub_efi_system_table->boot_services; > + status = b->install_multiple_protocol_interfaces (&initrd_lf2_handle, > + &load_file2_guid, > + &initrd_lf2, > + &device_path_guid, > + &initrd_lf2_device_path, > + NULL); > + if (status == GRUB_EFI_OUT_OF_RESOURCES) > + { > + grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory")); > + return grub_errno; > + } > + grub_dprintf ("linux", "LoadFile2 initrd loading protocol installed\n"); > + return GRUB_ERR_NONE; > + } > + > initrd_size = grub_get_initrd_size (&initrd_ctx); > grub_dprintf ("linux", "Loading initrd\n"); > > -- > 2.17.1 > -- Regards, Atish
