Re: [PATCH 3/4] efi_loader: install DXE services table

On 07.01.25 14:30, Ilias Apalodimas wrote:

On Thu, 2 Jan 2025 at 20:11, Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:

...

The debug version of the UEFI shell requires a DXE services table to exist.

Implement the table and let all DXE functions return EFI_UNSUPPORTED.

Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com

include/efi_dxe.h | 54 ++++++++++++ include/efi_loader.h | 7 ++ lib/efi_loader/Kconfig | 7 ++ lib/efi_loader/Makefile | 1 + lib/efi_loader/efi_dxe.c | 176 +++++++++++++++++++++++++++++++++++++ lib/efi_loader/efi_setup.c | 6 ++ 6 files changed, 251 insertions(+) create mode 100644 include/efi_dxe.h create mode 100644 lib/efi_loader/efi_dxe.c

diff --git a/include/efi_dxe.h b/include/efi_dxe.h new file mode 100644 index 00000000000..5623189de0c --- /dev/null +++ b/include/efi_dxe.h @@ -0,0 +1,54 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/*

• • DXE services table
• • Copyright (c) 2025 Heinrich Schuchardt
• */

+#ifndef _EFI_DXE_H +#define _EFI_DXE_H 1

+#include <efi.h>

+/**

• • define DXE_SERVICES_SIGNATURE - DXE services signature ('DXE_SERV')
• */

+#define DXE_SERVICES_SIGNATURE 0x565245535f455844 +/**

• • define DXE_SERVICES_REVISION - DXE services revision (1.8)
• */

+#define DXE_SERVICES_REVISION 0x00010050

+/**

• • define EFI_DXE_SERVICES_TABLE_GUID - GUID of the EFI DXE services table
• */

+#define EFI_DXE_SERVICES_TABLE_GUID \

•   EFI_GUID(0x5ad34ba, 0x6f02, 0x4214, \
  

•            0x95, 0x2e, 0x4d, 0xa0, 0x39, 0x8e, 0x2b, 0xb9)
  

+struct efi_dxe_services {

•   struct efi_table_hdr hdr;
  

•   efi_status_t (EFIAPI *add_memory_space)(void);
  

•   efi_status_t (EFIAPI *allocate_memory_space)(void);
  

•   efi_status_t (EFIAPI *free_memory_space)(void);
  

•   efi_status_t (EFIAPI *remove_memory_space)(void);
  

•   efi_status_t (EFIAPI *get_memory_space_descriptor)(void);
  

•   efi_status_t (EFIAPI *set_memory_space_attributes)(void);
  

•   efi_status_t (EFIAPI *get_memory_space_map)(void);
  

•   efi_status_t (EFIAPI *add_io_space)(void);
  

•   efi_status_t (EFIAPI *allocate_io_space)(void);
  

•   efi_status_t (EFIAPI *free_io_space)(void);
  

•   efi_status_t (EFIAPI *remove_io_space)(void);
  

•   efi_status_t (EFIAPI *get_io_space_descriptor)(void);
  

•   efi_status_t (EFIAPI *get_io_space_map)(void);
  

•   efi_status_t (EFIAPI *dispatch)(void);
  

•   efi_status_t (EFIAPI *schedule)(void);
  

•   efi_status_t (EFIAPI *trust)(void);
  

•   efi_status_t (EFIAPI *process_firmware_volume)(void);
  

•   efi_status_t (EFIAPI *set_memory_space_capabilities)(void);
  

+};

+extern efi_guid_t efi_dxe_services_table_guid;

+#endif /* _EFI_DXE_H */ diff --git a/include/efi_loader.h b/include/efi_loader.h index c1258098217..d474866184f 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -663,6 +663,13 @@ efi_status_t efi_smbios_register(void); */ efi_status_t efi_hob_list_register(void);

+/**

• • efi_dxe_services_register() - install DXE services table
• • Return: status code
• */

+efi_status_t efi_dxe_services_register(void);

• struct efi_simple_file_system_protocol * efi_fs_from_path(struct efi_device_path *fp);

diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index ec38a0ea352..ed3470508ff 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -384,6 +384,13 @@ config EFI_DT_FIXUP The EFI device-tree fix-up protocol provides a function to let the firmware apply fix-ups. This may be used by boot loaders.

+config EFI_DXE

•   bool 'DXE services table'
  

•   default y
  

•   help
  

•     Install the DXE services table. The debug version of the UEFI shell
  

•     requires it.
  

• config EFI_LOADER_HII bool "HII protocols" default y

diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index 195ed8667fe..4f250f21811 100644 --- a/lib/efi_loader/Makefile +++ b/lib/efi_loader/Makefile @@ -33,6 +33,7 @@ obj-y += efi_console.o obj-y += efi_device_path.o obj-$(CONFIG_EFI_DEVICE_PATH_TO_TEXT) += efi_device_path_to_text.o obj-$(CONFIG_EFI_DEVICE_PATH_UTIL) += efi_device_path_utilities.o +obj-$(CONFIG_EFI_DXE) += efi_dxe.o obj-y += efi_dt_fixup.o obj-y += efi_fdt.o obj-y += efi_file.o diff --git a/lib/efi_loader/efi_dxe.c b/lib/efi_loader/efi_dxe.c new file mode 100644 index 00000000000..f8920575b0c --- /dev/null +++ b/lib/efi_loader/efi_dxe.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/*

• • DXE services table
• • Copyright (c) 2025 Heinrich Schuchardt
• */

+#include <efi_dxe.h> +#include <efi_loader.h>

+efi_guid_t efi_dxe_services_table_guid = EFI_DXE_SERVICES_TABLE_GUID;

+static efi_status_t EFIAPI add_memory_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI allocate_memory_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI free_memory_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI remove_memory_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI get_memory_space_descriptor(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI set_memory_space_attributes(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI get_memory_space_map(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI add_io_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI allocate_io_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI free_io_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI remove_io_space(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI get_io_space_descriptor(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI get_io_space_map(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI dispatch(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI schedule(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI trust(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI process_firmware_volume(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static efi_status_t EFIAPI set_memory_space_capabilities(void) +{

•   EFI_ENTRY();
  

•   return EFI_EXIT(EFI_UNSUPPORTED);
  

+}

+static struct efi_dxe_services efi_dxe_services = {

•   .hdr = {
  

•           .signature = DXE_SERVICES_SIGNATURE,
  

•           .revision = DXE_SERVICES_REVISION,
  

•           .headersize = sizeof(struct efi_dxe_services),
  

•   },
  

•   .add_memory_space = add_memory_space,
  

•   .allocate_memory_space = allocate_memory_space,
  

•   .free_memory_space = free_memory_space,
  

•   .remove_memory_space = remove_memory_space,
  

•   .get_memory_space_descriptor = get_memory_space_descriptor,
  

•   .set_memory_space_attributes = set_memory_space_attributes,
  

•   .get_memory_space_map = get_memory_space_map,
  

•   .add_io_space = add_io_space,
  

•   .allocate_io_space = allocate_io_space,
  

•   .free_io_space = free_io_space,
  

•   .remove_io_space = remove_io_space,
  

•   .get_io_space_descriptor = get_io_space_descriptor,
  

•   .get_io_space_map = get_io_space_map,
  

•   .dispatch = dispatch,
  

•   .schedule = schedule,
  

•   .trust = trust,
  

•   .process_firmware_volume = process_firmware_volume,
  

•   .set_memory_space_capabilities = set_memory_space_capabilities,
  

Do we plan on ever implementing those? If not we could use a single function returning EFI_UNSUPPORTED instead of all of them for code size reasons

Currently I don't plan to implement these. But I wanted to be able to add

#define _DEBUG 1

to find out which of the functions is possibly used.

On x86 and sandbox I don't think our memory restrictions are very tight.

Best regards

Heinrich

Cheers /Ilias

...

+};

+efi_status_t efi_dxe_services_register(void) +{

•   struct efi_dxe_services *dxe;
  

•   dxe = efi_alloc(sizeof(struct efi_dxe_services));
  

•   if (!dxe)
  

•           return EFI_OUT_OF_RESOURCES;
  

•   memcpy(dxe, &efi_dxe_services, sizeof(struct efi_dxe_services));
  

•   return efi_install_configuration_table(&efi_dxe_services_table_guid, dxe);
  

+} diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c index 393b690c3ee..796da5d5678 100644 --- a/lib/efi_loader/efi_setup.c +++ b/lib/efi_loader/efi_setup.c @@ -260,6 +260,12 @@ efi_status_t efi_init_obj_list(void) if (ret != EFI_SUCCESS) goto out;

•   if (IS_ENABLED(CONFIG_EFI_DXE)) {
  

•           ret = efi_dxe_services_register();
  

•           if (ret != EFI_SUCCESS)
  

•                   goto out;
  

•   }
  

•    if (IS_ENABLED(CONFIG_EFI_ECPT)) {
             ret = efi_ecpt_register();
             if (ret != EFI_SUCCESS)
  

-- 2.47.1