Re: [PATCH] bootm: remove previously deprecated CONFIG_BOOTM_OPTEE
Ahmad Fatoum <[email protected]>
| Newsgroups | org.infradead.lists.barebox |
|---|---|
| Message-ID | <[email protected]> |
Hi, On 8/5/26 4:48 PM, Ahmad Fatoum wrote: > Early loading of OP-TEE for 32-bit platforms was added in 2020 shortly > after initial (late) loading support was added in 2019. > > CONFIG_BOOTM_OPTEE (practically OP-TEE in a FIT image alongside the > kernel) has been documented as deprecated since 2025 as it greatly > increases the trusted computing base by running all of barebox in > secure monitor mode as opposed to only the prebootloader. > > Additionally, a `tee =' key in the FIT is a barebox invention and the > spec conforming way would be to reference the tee in the loadables > property of a configuration. > > For all these reasons, let's finally remove late loading. > > Signed-off-by: Ahmad Fatoum <[email protected]> Any objections? Cheers, Ahmad > --- > .../migration-guides/migration-master.rst | 13 ++++ > Documentation/user/optee.rst | 12 ++-- > Documentation/user/security.rst | 3 - > arch/arm/cpu/start.c | 3 - > arch/arm/include/asm/armlinux.h | 2 +- > arch/arm/lib32/Makefile | 1 - > arch/arm/lib32/armlinux.c | 10 +-- > arch/arm/lib32/bootm.c | 64 +------------------ > arch/arm/lib32/bootu.c | 2 +- > arch/arm/lib32/bootz.c | 2 +- > arch/arm/lib32/start-kernel-optee.S | 16 ----- > commands/bootm.c | 11 +--- > common/bootm-android-image.c | 1 - > common/bootm-fit.c | 31 ++------- > common/bootm.c | 20 ++---- > drivers/tee/optee/Kconfig | 2 +- > include/bootm.h | 6 -- > include/loadable.h | 6 +- > lib/loadable.c | 2 - > security/Kconfig | 18 ------ > 20 files changed, 38 insertions(+), 187 deletions(-) > delete mode 100644 arch/arm/lib32/start-kernel-optee.S > > diff --git a/Documentation/migration-guides/migration-master.rst b/Documentation/migration-guides/migration-master.rst > index e28a608e53e9..68f0ef65756b 100644 > --- a/Documentation/migration-guides/migration-master.rst > +++ b/Documentation/migration-guides/migration-master.rst > @@ -17,3 +17,16 @@ ARCH=arm64 > Use of ``ARCH=arm`` for 64-bit ARM builds is deprecated and now emits > a warning. Users should change build scripts to use ``ARCH=arm64`` > instead when targetting ARMv8. > + > +Removal of deprecated CONFIG_BOOTM_OPTEE > +---------------------------------------- > + > +The support for late loading of OP-TEE had been deprecated and ultimately > +removed as it greatly increased the attack surface and was only supported > +on 32-bit ARM systems. > + > +OP-TEE loading is now only supported > +:ref:`in the prebootloader <optee_early_loading>`. > + > +For i.MX6 boards, this can be enabled by enabling > +``CONFIG_FIRMWARE_IMX6_OPTEE``. > diff --git a/Documentation/user/optee.rst b/Documentation/user/optee.rst > index 88e651ddec57..975dcdc3dbac 100644 > --- a/Documentation/user/optee.rst > +++ b/Documentation/user/optee.rst > @@ -39,15 +39,11 @@ main barebox start function. > Before Linux start > ^^^^^^^^^^^^^^^^^^ > > -.. warning:: Late loading of OP-TEE is deprecated, greatly increases the > - attack surface and is only supported on 32-bit ARM systems. > - Systems should prefer early loading OP-TEE whenever possible. > +The support for late loading of OP-TEE had been deprecated and ultimately > +removed as it greatly increased the attack surface and was only supported > +on 32-bit ARM systems. > +OP-TEE loading is now only supported :ref:`in the prebootloader <optee_early_loading>`. > > -Enable the `CONFIG_BOOTM_OPTEE` configuration variable and configure the > -`CONFIG_OPTEE_SIZE` variable. This will reserve a memory area at the end > -of memory for OP-TEE to run, usually Barebox would relocate itself there. To > -load OP-TEE before the kernel is started, configure the global ``bootm.tee`` > -variable to point to a valid OPTEE v1 binary. > > Communication with OP-TEE > ------------------------- > diff --git a/Documentation/user/security.rst b/Documentation/user/security.rst > index 94184ab8e893..f8cd6bd090f2 100644 > --- a/Documentation/user/security.rst > +++ b/Documentation/user/security.rst > @@ -69,9 +69,6 @@ Firmware) should happen as early as possible, i.e., within the barebox > barebox will run with elevated permission, which greatly increases the attack > surface. > > -In concrete terms, the deprecated ``CONFIG_BOOTM_OPTEE`` option should be > -disabled in favor of :ref:`loading OP-TEE early <optee_early_loading>`. > - > Ensuring the kernel is verified > ------------------------------- > > diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c > index 6a9941275c12..f9f380444f81 100644 > --- a/arch/arm/cpu/start.c > +++ b/arch/arm/cpu/start.c > @@ -192,9 +192,6 @@ __noreturn void barebox_non_pbl_start(unsigned long membase, > > handoff_data_set(hd); > > - if (IS_ENABLED(CONFIG_BOOTM_OPTEE)) > - of_add_reserve_entry(endmem - OPTEE_SIZE, endmem - 1); > - > pr_debug("starting barebox...\n"); > > start_barebox(); > diff --git a/arch/arm/include/asm/armlinux.h b/arch/arm/include/asm/armlinux.h > index 871664824643..83813a5dce97 100644 > --- a/arch/arm/include/asm/armlinux.h > +++ b/arch/arm/include/asm/armlinux.h > @@ -63,6 +63,6 @@ struct image_data; > > void start_linux(void *adr, int swap, unsigned long initrd_address, > unsigned long initrd_size, void *oftree, > - enum arm_security_state, void *optee); > + enum arm_security_state); > > #endif /* __ARCH_ARMLINUX_H */ > diff --git a/arch/arm/lib32/Makefile b/arch/arm/lib32/Makefile > index 67c4f16f76ad..5598ab386052 100644 > --- a/arch/arm/lib32/Makefile > +++ b/arch/arm/lib32/Makefile > @@ -3,7 +3,6 @@ > obj-$(CONFIG_ARM_LINUX) += armlinux.o > obj-$(CONFIG_CMD_BOOTZ) += bootz.o > obj-$(CONFIG_BOOTM) += bootm.o > -obj-$(CONFIG_BOOTM_OPTEE) += start-kernel-optee.o > obj-$(CONFIG_CMD_BOOTU) += bootu.o > obj-$(CONFIG_BOOT_ATAGS) += atags.o > obj-y += div0.o > diff --git a/arch/arm/lib32/armlinux.c b/arch/arm/lib32/armlinux.c > index 6890d9cb6fda..8bb3c5f9c273 100644 > --- a/arch/arm/lib32/armlinux.c > +++ b/arch/arm/lib32/armlinux.c > @@ -28,11 +28,9 @@ > #include <asm/secure.h> > #include <asm/boot.h> > > -void start_kernel_optee(void *optee, void *kernel, void *oftree); > - > void start_linux(void *adr, int swap, unsigned long initrd_address, > unsigned long initrd_size, void *oftree, > - enum arm_security_state state, void *optee) > + enum arm_security_state state) > { > phys_addr_t params = 0; > unsigned architecture; > @@ -79,9 +77,5 @@ void start_linux(void *adr, int swap, unsigned long initrd_address, > __asm__ __volatile__("mcr p15, 0, %0, c1, c0" :: "r" (reg)); > } > > - if (optee && IS_ENABLED(CONFIG_BOOTM_OPTEE)) { > - start_kernel_optee(optee, adr, oftree); > - } else { > - __jump_to_linux(adr, architecture, params); > - } > + __jump_to_linux(adr, architecture, params); > } > diff --git a/arch/arm/lib32/bootm.c b/arch/arm/lib32/bootm.c > index e94bb979eff9..e2a80ada788b 100644 > --- a/arch/arm/lib32/bootm.c > +++ b/arch/arm/lib32/bootm.c > @@ -21,7 +21,6 @@ > #include <binfmt.h> > #include <restart.h> > #include <globalvar.h> > -#include <tee/optee.h> > #include <asm/byteorder.h> > #include <asm/setup.h> > #include <asm/barebox-arm.h> > @@ -149,54 +148,6 @@ static int get_kernel_addresses(size_t image_size, > return 0; > } > > -static int optee_verify_header_request_region(struct image_data *data, struct optee_header *hdr) > -{ > - int ret; > - > - ret = optee_verify_header(hdr); > - if (ret < 0) { > - pr_err("Could not verify header: %pe", ERR_PTR(ret)); > - return ret; > - } > - > - data->tee_res = request_sdram_region("TEE", hdr->init_load_addr_lo, hdr->init_size, > - MEMTYPE_RESERVED, MEMATTRS_RW_DEVICE); > - if (!data->tee_res) > - return -EINVAL; > - > - return 0; > -} > - > -static int bootm_load_tee(struct image_data *data) > -{ > - int ret; > - struct optee_header hdr; > - > - if (!data->tee) > - return 0; > - > - ret = loadable_extract_into_buf(data->tee, &hdr, sizeof(hdr), 0, > - LOADABLE_EXTRACT_PARTIAL); > - if (ret < 0) > - return ret; > - > - ret = optee_verify_header_request_region(data, &hdr); > - if (ret < 0) > - return ret; > - > - ret = loadable_extract_into_buf(data->tee, (void *)data->tee_res->start, > - hdr.init_size, sizeof(hdr), 0); > - if (ret < 0) { > - release_region(data->tee_res); > - return ret; > - } > - > - printf("Loaded TEE image to %pa, size 0x%08x\n", > - (void *)data->tee_res->start, hdr.init_size); > - > - return 0; > -} > - > static int __do_bootm_linux(struct image_data *data, unsigned long free_mem, > int swap, void *fdt) > { > @@ -204,7 +155,6 @@ static int __do_bootm_linux(struct image_data *data, unsigned long free_mem, > unsigned long initrd_start = 0, initrd_size = 0, initrd_end = 0; > const struct resource *initrd_res, *sdram; > struct resource gap; > - void *tee; > enum arm_security_state state = bootm_arm_security_state(); > void *fdt_load_address = NULL; > int ret; > @@ -259,13 +209,6 @@ static int __do_bootm_linux(struct image_data *data, unsigned long free_mem, > return PTR_ERR(fdt_res); > } > > - if (IS_ENABLED(CONFIG_BOOTM_OPTEE)) { > - ret = bootm_load_tee(data); > - if (ret) > - return ret; > - } > - > - > if (bootm_verbose(data)) { > printf("\nStarting kernel at 0x%08lx", kernel); > if (initrd_size) > @@ -291,13 +234,8 @@ static int __do_bootm_linux(struct image_data *data, unsigned long free_mem, > if (ret) > return ret; > > - if (data->tee_res) > - tee = (void *)data->tee_res->start; > - else > - tee = NULL; > - > start_linux((void *)kernel, swap, initrd_start, initrd_size, > - fdt_load_address, state, tee); > + fdt_load_address, state); > > restart_machine(0); > > diff --git a/arch/arm/lib32/bootu.c b/arch/arm/lib32/bootu.c > index 4b0f495aea5f..f7b6ccc8c651 100644 > --- a/arch/arm/lib32/bootu.c > +++ b/arch/arm/lib32/bootu.c > @@ -36,7 +36,7 @@ static int do_bootu(int argc, char *argv[]) > if (ret) > return ret; > > - start_linux(kernel, 0, 0, 0, oftree, ARM_STATE_SECURE, NULL); > + start_linux(kernel, 0, 0, 0, oftree, ARM_STATE_SECURE); > > return 1; > } > diff --git a/arch/arm/lib32/bootz.c b/arch/arm/lib32/bootz.c > index 5aa762b4912d..97607e43a645 100644 > --- a/arch/arm/lib32/bootz.c > +++ b/arch/arm/lib32/bootz.c > @@ -120,7 +120,7 @@ static int do_bootz(int argc, char *argv[]) > if (ret) > return ret; > > - start_linux(zimage, swap, 0, 0, oftree, ARM_STATE_SECURE, NULL); > + start_linux(zimage, swap, 0, 0, oftree, ARM_STATE_SECURE); > > return 0; > > diff --git a/arch/arm/lib32/start-kernel-optee.S b/arch/arm/lib32/start-kernel-optee.S > deleted file mode 100644 > index 261ab39ba7a3..000000000000 > --- a/arch/arm/lib32/start-kernel-optee.S > +++ /dev/null > @@ -1,16 +0,0 @@ > -/* SPDX-License-Identifier: GPL-2.0-only */ > - > -#include <linux/linkage.h> > - > -ENTRY(start_kernel_optee) > - /* > - * r0 = optee > - * r1 = kernel > - * r2 = oftree > - */ > - mov r4, r0 > - mov r0, #0 > - mov lr, r1 > - mov r1, #0 > - bx r4 > -ENDPROC(start_kernel_optee) > diff --git a/commands/bootm.c b/commands/bootm.c > index 24bce5ce6b64..9ff4b218fd1f 100644 > --- a/commands/bootm.c > +++ b/commands/bootm.c > @@ -28,7 +28,7 @@ > #include <magicvar.h> > #include <asm-generic/memory_layout.h> > > -#define BOOTM_OPTS_COMMON "sca:e:vo:fdt:" > +#define BOOTM_OPTS_COMMON "sca:e:vo:fd" > > #ifdef CONFIG_BOOTM_INITRD > #define BOOTM_OPTS BOOTM_OPTS_COMMON "L:r:" > @@ -88,9 +88,6 @@ static int do_bootm(int argc, char *argv[]) > case 'd': > data.dryrun = 1; > break; > - case 't': > - data.tee_file = optarg; > - break; > default: > return COMMAND_ERROR_USAGE; > } > @@ -129,9 +126,6 @@ BAREBOX_CMD_HELP_OPT ("-e OFFS\t","entry point to the image relative to start (0 > #ifdef CONFIG_OFTREE > BAREBOX_CMD_HELP_OPT ("-o DTB\t","specify open firmware device tree") > #endif > -#ifdef CONFIG_BOOTM_OPTEE > -BAREBOX_CMD_HELP_OPT ("-t TEE\t","specify TEE image") > -#endif > #ifdef CONFIG_BOOTM_VERBOSE > BAREBOX_CMD_HELP_OPT ("-v\t","verbose") > #endif > @@ -150,9 +144,6 @@ BAREBOX_CMD_START(bootm) > #endif > #ifdef CONFIG_BOOTM_VERBOSE > "v" > -#endif > -#ifdef CONFIG_BOOTM_OPTEE > - "t" > #endif > "] IMAGE") > BAREBOX_CMD_GROUP(CMD_GRP_BOOT) > diff --git a/common/bootm-android-image.c b/common/bootm-android-image.c > index 6acc41c3dd66..f48c97741528 100644 > --- a/common/bootm-android-image.c > +++ b/common/bootm-android-image.c > @@ -54,7 +54,6 @@ static int do_bootm_aimage(struct image_data *img_data) > struct bootm_data bootm_data = { > .oftree_file = img_data->oftree_file, > .initrd_file = img_data->initrd_file, > - .tee_file = img_data->tee_file, > .verbose = img_data->verbose, > .verify = img_data->verify, > .force = img_data->force, > diff --git a/common/bootm-fit.c b/common/bootm-fit.c > index 995bd7181223..f7742b871785 100644 > --- a/common/bootm-fit.c > +++ b/common/bootm-fit.c > @@ -87,30 +87,6 @@ static bool loadable_from_fit_oftree(struct image_data *data, > return true; > } > > -/* > - * loadable_from_fit_tee() - create tee loadable from FIT > - * @data: image data context > - * @fit: handle of FIT image > - * @config: config to look up kernel in > - * > - * This creates a loadable for the first trusted execution environment > - * in the config. > - * > - * Return: true if a TEE exists or > - * false otherwise. > - */ > -static bool loadable_from_fit_tee(struct image_data *data, > - struct fit_handle *fit, > - void *config) > -{ > - if (!fit_has_image(fit, config, "tee")) > - return false; > - > - loadable_release(&data->tee); > - data->tee = loadable_from_fit(fit, config, "tee", 0, LOADABLE_TEE); > - return true; > -} > - > static bool bootm_fit_config_valid(struct fit_handle *fit, > struct device_node *config) > { > @@ -164,6 +140,12 @@ int bootm_open_fit(struct image_data *data, bool override) > goto err; > } > > + if (fit_has_image(fit, fit_config, "tee")) { > + pr_err("Late-loaded tee is insecure and no longer supported\n"); > + ret = -ENOSYS; > + goto err; > + } > + > loadable_from_fit_os(data, fit, fit_config); > if (override) > data->is_override.os = true; > @@ -171,7 +153,6 @@ int bootm_open_fit(struct image_data *data, bool override) > data->is_override.initrd = true; > if (loadable_from_fit_oftree(data, fit, fit_config) && override) > data->is_override.oftree = true; > - loadable_from_fit_tee(data, fit, fit_config); > > data->kernel_type = bootm_fit_update_os_header(data); > > diff --git a/common/bootm.c b/common/bootm.c > index de1b87fe2072..27da1a590bf1 100644 > --- a/common/bootm.c > +++ b/common/bootm.c > @@ -95,7 +95,6 @@ void bootm_data_init_defaults(struct bootm_data *data) > data->os_address = UIMAGE_SOME_ADDRESS; > data->os_entry = UIMAGE_SOME_ADDRESS; > data->oftree_file = getenv_nonempty("global.bootm.oftree"); > - data->tee_file = getenv_nonempty("global.bootm.tee"); > data->os_file = getenv_nonempty("global.bootm.image"); > getenv_ul("global.bootm.image.loadaddr", &data->os_address); > if (IS_ENABLED(CONFIG_BOOTM_INITRD)) { > @@ -117,7 +116,6 @@ void bootm_data_init_defaults(struct bootm_data *data) > void bootm_data_restore_defaults(const struct bootm_data *data) > { > globalvar_set("bootm.oftree", data->oftree_file); > - globalvar_set("bootm.tee", data->tee_file); > globalvar_set("bootm.image", data->os_file); > pr_setenv("global.bootm.image.loadaddr", "0x%lx", data->os_address); > if (IS_ENABLED(CONFIG_BOOTM_INITRD)) { > @@ -495,12 +493,6 @@ static int bootm_open_files(struct image_data *data) > return ret; > } > > - if (data->tee_file) { > - data->tee = loadable_from_file(data->tee_file, LOADABLE_TEE); > - if (IS_ERR(data->tee)) > - return PTR_ERR(data->tee); > - } > - > return 0; > } > > @@ -545,13 +537,16 @@ struct image_data *bootm_boot_prep(const struct bootm_data *bootm_data) > return ERR_PTR(-ENOENT); > } > > + if (nonempty(globalvar_get("bootm.tee"))) { > + pr_err("Late-loaded tee is insecure and no longer supported\n"); > + return ERR_PTR(-ENOSYS); > + } > + > data = xzalloc(sizeof(*data)); > > bootm_image_name_and_part(bootm_data->os_file, &data->os_file, &data->os_part); > bootm_image_name_and_part(bootm_data->oftree_file, &data->oftree_file, &data->oftree_part); > bootm_image_name_and_part(bootm_data->initrd_file, &data->initrd_file, &data->initrd_part); > - if (bootm_data->tee_file) > - data->tee_file = xstrdup(bootm_data->tee_file); > data->verbose = bootm_data->verbose; > data->verify = bootm_data->verify; > data->force = bootm_data->force; > @@ -581,7 +576,6 @@ struct image_data *bootm_boot_prep(const struct bootm_data *bootm_data) > */ > data->oftree_file = NULL; > data->initrd_file = NULL; > - data->tee_file = NULL; > if (data->image_type != filetype_fit) { > pr_err("Signed boot and image is no FIT image, aborting\n"); > ret = -EINVAL; > @@ -803,11 +797,9 @@ void bootm_boot_cleanup(struct image_data *data) > of_del_reserve_entry(data->initrd_res->start, data->initrd_res->end); > release_sdram_region(data->initrd_res); > release_sdram_region(data->oftree_res); > - release_sdram_region(data->tee_res); > loadable_release(&data->oftree); > loadable_release(&data->initrd); > loadable_release(&data->os); > - loadable_release(&data->tee); > if (data->of_root_node) > of_delete_node(data->of_root_node); > > @@ -816,7 +808,6 @@ void bootm_boot_cleanup(struct image_data *data) > free(data->os_file); > free(data->oftree_file); > free(data->initrd_file); > - free(data->tee_file); > free(data); > } > > @@ -921,7 +912,6 @@ BAREBOX_MAGICVAR(global.bootm.image.loadaddr, "bootm default boot image loadaddr > BAREBOX_MAGICVAR(global.bootm.initrd, "bootm default initrd"); > BAREBOX_MAGICVAR(global.bootm.initrd.loadaddr, "bootm default initrd loadaddr"); > BAREBOX_MAGICVAR(global.bootm.oftree, "bootm default oftree"); > -BAREBOX_MAGICVAR(global.bootm.tee, "bootm default tee image"); > BAREBOX_MAGICVAR(global.bootm.dryrun, "bootm default dryrun level"); > BAREBOX_MAGICVAR(global.bootm.verify, "bootm default verify level"); > #ifdef CONFIG_EFI_LOADER > diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig > index fcaca29a5df7..73e77d0559c4 100644 > --- a/drivers/tee/optee/Kconfig > +++ b/drivers/tee/optee/Kconfig > @@ -18,7 +18,7 @@ config OPTEE > For more information see: https://www.op-tee.org > > This driver doesn't actually load OP-TEE. For that see > - CONFIG_BOOTM_OPTEE and PBL_OPTEE. > + CONFIG_PBL_OPTEE. > > If unsure, say n here. > > diff --git a/include/bootm.h b/include/bootm.h > index 1a556e1e95b5..946713971eb5 100644 > --- a/include/bootm.h > +++ b/include/bootm.h > @@ -24,7 +24,6 @@ struct bootm_data { > const char *os_file; > const char *initrd_file; > const char *oftree_file; > - const char *tee_file; > const char *root_dev; > const char *root_param; > int verbose; > @@ -130,11 +129,6 @@ struct image_data { > * it. > */ > void *os_header; > - char *tee_file; > - struct resource *tee_res; > - > - /* Future default case: A generic loadable object */ > - struct loadable *tee; > > /* Type of OS image, e.g. filetype_fit or the same as kernel_type */ > enum filetype image_type; > diff --git a/include/loadable.h b/include/loadable.h > index 79b1579be291..9cc89ea4581c 100644 > --- a/include/loadable.h > +++ b/include/loadable.h > @@ -17,14 +17,12 @@ struct loadable; > * @LOADABLE_KERNEL: kernel image > * @LOADABLE_INITRD: initial ramdisk > * @LOADABLE_FDT: flattened device tree > - * @LOADABLE_TEE: trusted execution environment > */ > enum loadable_type { > LOADABLE_UNSPECIFIED, > LOADABLE_KERNEL, > LOADABLE_INITRD, > LOADABLE_FDT, > - LOADABLE_TEE, > }; > > /** > @@ -130,7 +128,7 @@ struct loadable_ops { > /** > * struct loadable - lazy-loadable boot component > * @name: descriptive name for debugging > - * @type: type of component (kernel, initrd, fdt, tee) > + * @type: type of component (kernel, initrd, fdt) > * @ops: operations for this loadable > * @priv: format-specific private data > * @info: cached metadata populated by get_info() > @@ -139,7 +137,7 @@ struct loadable_ops { > * @chained_loadables: list of additional loadables chained to this one > * @list: list node for chained_loadables > * > - * Represents something that can be loaded to RAM (kernel, initrd, fdt, tee). > + * Represents something that can be loaded to RAM (kernel, initrd, fdt). > * Metadata can be queried without loading. Actual loading happens on extract > * or via mmap. > */ > diff --git a/lib/loadable.c b/lib/loadable.c > index 65121a7dbf90..8c016c125d87 100644 > --- a/lib/loadable.c > +++ b/lib/loadable.c > @@ -31,8 +31,6 @@ const char *loadable_type_tostr(enum loadable_type type) > return "initrd"; > case LOADABLE_FDT: > return "fdt"; > - case LOADABLE_TEE: > - return "tee"; > default: > return NULL; > } > diff --git a/security/Kconfig b/security/Kconfig > index b14803348b68..cb5cc2b92bc2 100644 > --- a/security/Kconfig > +++ b/security/Kconfig > @@ -156,24 +156,6 @@ config OPTEE_SHM_SIZE > mode supported by barebox anyway, but support needs to be enabled > in OP-TEE at compile-time. > > -config BOOTM_OPTEE > - bool > - prompt "support booting OP-TEE" > - depends on BOOTM && ARM32 > - select HAVE_OPTEE > - select HAS_INSECURE_DEFAULTS > - help > - OP-TEE is a trusted execution environment (TEE). With this option > - enabled barebox supports starting optee_os as part of the bootm command. > - Instead of the kernel bootm starts the optee_os binary which then starts > - the kernel in nonsecure mode. Pass the optee_os binary with the -t option > - or in the global.bootm.tee variable. > - > - This mode of late loading OP-TEE just before the kernel is deprecated > - in favor of early loading OP-TEE in the PBL (CONFIG_PBL_OPTEE). > - Early-loading greatly reduces the attack surface and is the only mode > - supported outside of ARMv7. > - > config PBL_OPTEE > bool "Enable OP-TEE early start" > depends on ARM -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |