| Message ID | 20250617120855.87492-2-paulliu@debian.org |
|---|---|
| State | New |
| Headers | show |
| Series | Add EFI Debug Support Table feature | expand |
On 6/17/25 14:08, Ying-Chun Liu (PaulLiu) wrote: > From: "Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org> > > Add EFI_SYSTEM_TABLE_POINTER structure for remote debugger to locate > the address of EFI_SYSTEM_TABLE. > > This feature is described in UEFI SPEC version 2.10. Section 18.4.2. > The implementation ensures support for hardware-assisted debugging and > provides a standardized mechanism for debuggers to discover the EFI > system table. > > Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org> > Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> > Cc: Peter Robinson <pbrobinson@gmail.com> > Cc: Simon Glass <sjg@chromium.org> > --- > V2: add Kconfig options to turn on/off this feature. > V3: make efi_initialize_system_table_pointer() do the job as described. > V4: use efi_alloc_aligned_pages() for system_table_pointer. > V5: move the code into a separate module. > V6: Use macros to replace size_4MB > --- > include/efi_api.h | 16 +++++++++++ > include/efi_loader.h | 2 ++ > lib/efi_loader/Kconfig | 8 ++++++ > lib/efi_loader/Makefile | 1 + > lib/efi_loader/efi_debug_support.c | 46 ++++++++++++++++++++++++++++++ > lib/efi_loader/efi_setup.c | 8 ++++++ > 6 files changed, 81 insertions(+) > create mode 100644 lib/efi_loader/efi_debug_support.c > > diff --git a/include/efi_api.h b/include/efi_api.h > index eb61eafa028..6c4c1a0cc7b 100644 > --- a/include/efi_api.h > +++ b/include/efi_api.h > @@ -259,6 +259,22 @@ struct efi_capsule_result_variable_header { > efi_status_t capsule_status; > } __packed; > > +/** > + * struct efi_system_table_pointer - struct to store the pointer of system > + * table. > + * @signature: The signature of this struct. > + * @efi_system_table_base: The physical address of System Table. > + * @crc32: CRC32 checksum > + * > + * This struct is design for hardware debugger to search through memory to > + * get the address of EFI System Table. > + */ > +struct efi_system_table_pointer { > + u64 signature; > + efi_physical_addr_t efi_system_table_base; > + u32 crc32; > +}; > + > struct efi_memory_range { > efi_physical_addr_t address; > u64 length; > diff --git a/include/efi_loader.h b/include/efi_loader.h > index 8f9f2bcf1cb..8f065244d8e 100644 > --- a/include/efi_loader.h > +++ b/include/efi_loader.h > @@ -646,6 +646,8 @@ efi_status_t efi_tcg2_measure_dtb(void *dtb); > efi_status_t efi_root_node_register(void); > /* Called by bootefi to initialize runtime */ > efi_status_t efi_initialize_system_table(void); > +/* Called by bootefi to initialize debug */ > +efi_status_t efi_initialize_system_table_pointer(void); > /* efi_runtime_detach() - detach unimplemented runtime functions */ > void efi_runtime_detach(void); > /* efi_convert_pointer() - convert pointer to virtual address */ > diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig > index 7f02a83e2a2..f9d75cbc3fd 100644 > --- a/lib/efi_loader/Kconfig > +++ b/lib/efi_loader/Kconfig > @@ -71,6 +71,14 @@ config EFI_SECURE_BOOT > config EFI_SIGNATURE_SUPPORT > bool > > +config EFI_DEBUG_SUPPORT > + bool "EFI Debug Support" There should be at least one defconfig using the setting so that we at least compile the new code in our CI. > + help > + Select this option if you want to setup the EFI Debug Support > + Table and the EFI_SYSTEM_TABLE_POINTER which is used by the debug > + agent or an external debugger to determine loaded image information > + in a quiescent manner. > + > menu "UEFI services" > > config EFI_GET_TIME > diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile > index cf050e5385d..51ccf1cd87e 100644 > --- a/lib/efi_loader/Makefile > +++ b/lib/efi_loader/Makefile > @@ -70,6 +70,7 @@ obj-$(CONFIG_EFI_RISCV_BOOT_PROTOCOL) += efi_riscv.o > obj-$(CONFIG_EFI_LOAD_FILE2_INITRD) += efi_load_initrd.o > obj-$(CONFIG_EFI_SIGNATURE_SUPPORT) += efi_signature.o > obj-$(CONFIG_EFI_ECPT) += efi_conformance.o > +obj-$(CONFIG_EFI_DEBUG_SUPPORT) += efi_debug_support.o > > EFI_VAR_SEED_FILE := $(subst $\",,$(CONFIG_EFI_VAR_SEED_FILE)) > $(obj)/efi_var_seed.o: $(srctree)/$(EFI_VAR_SEED_FILE) > diff --git a/lib/efi_loader/efi_debug_support.c b/lib/efi_loader/efi_debug_support.c > new file mode 100644 > index 00000000000..3794b31c4cd > --- /dev/null > +++ b/lib/efi_loader/efi_debug_support.c > @@ -0,0 +1,46 @@ > +// SPDX-License-Identifier: GPL-2.0+ GPL-2.0-or-later see https://spdx.org/licenses/GPL-2.0-or-later.html > +/* > + * EFI application boot time services > + * > + * Copyright (c) 2025 Ying-Chun Liu, Linaro Ltd. <paul.liu@linaro.org> > + */ > + > +#include <efi_loader.h> > +#include <linux/sizes.h> > +#include <u-boot/crc.h> > + > +struct efi_system_table_pointer __efi_runtime_data * systab_pointer = NULL; > + > +/** > + * efi_initialize_system_table_pointer() - Initialize system table pointer > + * > + * Return: status code > + */ > +efi_status_t efi_initialize_system_table_pointer(void) > +{ > + uintptr_t addr; > + u32 crc32_value; > + > + /* Allocate configuration table array */ This comment does not match the allocated object. > + addr = (uintptr_t)efi_alloc_aligned_pages(sizeof(struct efi_system_table_pointer), > + EFI_RUNTIME_SERVICES_DATA, > + SZ_4M); Please, assign system_pointer here directly and avoid unnecessary conversions (void *) -> (uintptr_t) -> (struct efi_system_table_pointer *). > + > + if (!addr) { > + log_err("Installing EFI system table pointer failed\n"); > + return EFI_OUT_OF_RESOURCES; > + } > + > + systab_pointer = (struct efi_system_table_pointer *)addr; > + memset(systab_pointer, 0, sizeof(struct efi_system_table_pointer)); > + > + systab_pointer->signature = EFI_SYSTEM_TABLE_SIGNATURE; > + systab_pointer->efi_system_table_base = (efi_physical_addr_t)&systab; > + > + crc32_value = crc32(0, > + (const unsigned char *)systab_pointer, > + sizeof(struct efi_system_table_pointer)); > + systab_pointer->crc32 = crc32_value; You can do that assignment directly without extra variable. > + > + return EFI_SUCCESS; > +} > diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c > index 48f91da5df7..6193b9f6d0c 100644 > --- a/lib/efi_loader/efi_setup.c > +++ b/lib/efi_loader/efi_setup.c > @@ -278,6 +278,14 @@ efi_status_t efi_init_obj_list(void) > if (ret != EFI_SUCCESS) > goto out; > > + /* Initialize system table pointer */ > + if (IS_ENABLED(CONFIG_EFI_DEBUG_SUPPORT)) { > + ret = efi_initialize_system_table_pointer(); > + if (ret != EFI_SUCCESS) { > + goto out; > + } Running scripts/checkpatch.pl will indicated that the braces should be avoided here to achieve adherence to the kernel style. Best regards Heinrich > + } > + > if (IS_ENABLED(CONFIG_EFI_ECPT)) { > ret = efi_ecpt_register(); > if (ret != EFI_SUCCESS)
diff --git a/include/efi_api.h b/include/efi_api.h index eb61eafa028..6c4c1a0cc7b 100644 --- a/include/efi_api.h +++ b/include/efi_api.h @@ -259,6 +259,22 @@ struct efi_capsule_result_variable_header { efi_status_t capsule_status; } __packed; +/** + * struct efi_system_table_pointer - struct to store the pointer of system + * table. + * @signature: The signature of this struct. + * @efi_system_table_base: The physical address of System Table. + * @crc32: CRC32 checksum + * + * This struct is design for hardware debugger to search through memory to + * get the address of EFI System Table. + */ +struct efi_system_table_pointer { + u64 signature; + efi_physical_addr_t efi_system_table_base; + u32 crc32; +}; + struct efi_memory_range { efi_physical_addr_t address; u64 length; diff --git a/include/efi_loader.h b/include/efi_loader.h index 8f9f2bcf1cb..8f065244d8e 100644 --- a/include/efi_loader.h +++ b/include/efi_loader.h @@ -646,6 +646,8 @@ efi_status_t efi_tcg2_measure_dtb(void *dtb); efi_status_t efi_root_node_register(void); /* Called by bootefi to initialize runtime */ efi_status_t efi_initialize_system_table(void); +/* Called by bootefi to initialize debug */ +efi_status_t efi_initialize_system_table_pointer(void); /* efi_runtime_detach() - detach unimplemented runtime functions */ void efi_runtime_detach(void); /* efi_convert_pointer() - convert pointer to virtual address */ diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index 7f02a83e2a2..f9d75cbc3fd 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -71,6 +71,14 @@ config EFI_SECURE_BOOT config EFI_SIGNATURE_SUPPORT bool +config EFI_DEBUG_SUPPORT + bool "EFI Debug Support" + help + Select this option if you want to setup the EFI Debug Support + Table and the EFI_SYSTEM_TABLE_POINTER which is used by the debug + agent or an external debugger to determine loaded image information + in a quiescent manner. + menu "UEFI services" config EFI_GET_TIME diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile index cf050e5385d..51ccf1cd87e 100644 --- a/lib/efi_loader/Makefile +++ b/lib/efi_loader/Makefile @@ -70,6 +70,7 @@ obj-$(CONFIG_EFI_RISCV_BOOT_PROTOCOL) += efi_riscv.o obj-$(CONFIG_EFI_LOAD_FILE2_INITRD) += efi_load_initrd.o obj-$(CONFIG_EFI_SIGNATURE_SUPPORT) += efi_signature.o obj-$(CONFIG_EFI_ECPT) += efi_conformance.o +obj-$(CONFIG_EFI_DEBUG_SUPPORT) += efi_debug_support.o EFI_VAR_SEED_FILE := $(subst $\",,$(CONFIG_EFI_VAR_SEED_FILE)) $(obj)/efi_var_seed.o: $(srctree)/$(EFI_VAR_SEED_FILE) diff --git a/lib/efi_loader/efi_debug_support.c b/lib/efi_loader/efi_debug_support.c new file mode 100644 index 00000000000..3794b31c4cd --- /dev/null +++ b/lib/efi_loader/efi_debug_support.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * EFI application boot time services + * + * Copyright (c) 2025 Ying-Chun Liu, Linaro Ltd. <paul.liu@linaro.org> + */ + +#include <efi_loader.h> +#include <linux/sizes.h> +#include <u-boot/crc.h> + +struct efi_system_table_pointer __efi_runtime_data * systab_pointer = NULL; + +/** + * efi_initialize_system_table_pointer() - Initialize system table pointer + * + * Return: status code + */ +efi_status_t efi_initialize_system_table_pointer(void) +{ + uintptr_t addr; + u32 crc32_value; + + /* Allocate configuration table array */ + addr = (uintptr_t)efi_alloc_aligned_pages(sizeof(struct efi_system_table_pointer), + EFI_RUNTIME_SERVICES_DATA, + SZ_4M); + + if (!addr) { + log_err("Installing EFI system table pointer failed\n"); + return EFI_OUT_OF_RESOURCES; + } + + systab_pointer = (struct efi_system_table_pointer *)addr; + memset(systab_pointer, 0, sizeof(struct efi_system_table_pointer)); + + systab_pointer->signature = EFI_SYSTEM_TABLE_SIGNATURE; + systab_pointer->efi_system_table_base = (efi_physical_addr_t)&systab; + + crc32_value = crc32(0, + (const unsigned char *)systab_pointer, + sizeof(struct efi_system_table_pointer)); + systab_pointer->crc32 = crc32_value; + + return EFI_SUCCESS; +} diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c index 48f91da5df7..6193b9f6d0c 100644 --- a/lib/efi_loader/efi_setup.c +++ b/lib/efi_loader/efi_setup.c @@ -278,6 +278,14 @@ efi_status_t efi_init_obj_list(void) if (ret != EFI_SUCCESS) goto out; + /* Initialize system table pointer */ + if (IS_ENABLED(CONFIG_EFI_DEBUG_SUPPORT)) { + ret = efi_initialize_system_table_pointer(); + if (ret != EFI_SUCCESS) { + goto out; + } + } + if (IS_ENABLED(CONFIG_EFI_ECPT)) { ret = efi_ecpt_register(); if (ret != EFI_SUCCESS)