po 7. 2. 2022 v 19:22 odesÃlatel Sughosh Ganu <sughosh.g...@linaro.org> napsal:
>
> The FWU Multi Bank Update specification requires the Update Agent to
> carry out certain checks at the time of platform boot. The Update
> Agent is the component which is responsible for updating the firmware
> components and maintaining and keeping the metadata in sync.
>
> The spec requires that the Update Agent perform the following checks
> at the time of boot
> * Sanity check of both the metadata copies maintained by the platform.
> * Get the boot index passed to U-Boot by the prior stage bootloader
> and use this value for metadata bookkeeping.
> * Check if the system is booting in Trial State. If the system boots
> in the Trial State for more than a specified number of boot counts,
> change the Active Bank to be booting the platform from.
>
> Add these checks in the board initialisation sequence, invoked after
> relocation.
>
> Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org>
> ---
>
> Changes since V3:
> * Change the TrialStateCtr efi variable attribute to remove the
> runtime attribute
>
> common/board_r.c | 6 ++
> include/fwu.h | 3 +
> lib/fwu_updates/fwu.c | 178 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 187 insertions(+)
> create mode 100644 lib/fwu_updates/fwu.c
>
> diff --git a/common/board_r.c b/common/board_r.c
> index 31a59c585a..81678870b9 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -78,6 +78,9 @@
> #ifdef CONFIG_EFI_SETUP_EARLY
> #include <efi_loader.h>
> #endif
> +#ifdef CONFIG_FWU_MULTI_BANK_UPDATE
> +#include <fwu.h>
> +#endif
>
> DECLARE_GLOBAL_DATA_PTR;
>
> @@ -805,6 +808,9 @@ static init_fnc_t init_sequence_r[] = {
> #endif
> #ifdef CONFIG_EFI_SETUP_EARLY
> (init_fnc_t)efi_init_obj_list,
> +#endif
> +#ifdef CONFIG_FWU_MULTI_BANK_UPDATE
> + fwu_boottime_checks,
> #endif
> run_main_loop,
> };
> diff --git a/include/fwu.h b/include/fwu.h
> index 90b8cd41e5..5a329d9ef7 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -37,6 +37,9 @@ struct fwu_mdata_ops {
> EFI_GUID(0x8a7a84a0, 0x8387, 0x40f6, 0xab, 0x41, \
> 0xa8, 0xb9, 0xa5, 0xa6, 0x0d, 0x23)
>
> +int fwu_boottime_checks(void);
> +u8 fwu_update_checks_pass(void);
> +
> int fwu_get_mdata(struct fwu_mdata **mdata);
> int fwu_update_mdata(struct fwu_mdata *mdata);
> int fwu_get_active_index(u32 *active_idx);
> diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
> new file mode 100644
> index 0000000000..86933123e7
> --- /dev/null
> +++ b/lib/fwu_updates/fwu.c
> @@ -0,0 +1,178 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2021, Linaro Limited
> + */
> +
> +#include <dm.h>
> +#include <efi.h>
> +#include <efi_loader.h>
> +#include <efi_variable.h>
> +#include <fwu.h>
> +#include <fwu_mdata.h>
> +#include <malloc.h>
> +
> +#include <linux/errno.h>
> +#include <linux/types.h>
> +
> +static u8 trial_state = 0;
> +static u8 boottime_check = 0;
you don't need to initialize them to 0. They are in bss which is setup
to 0 already.
> +
> +static int fwu_trial_state_check(void)
> +{
> + int ret, i;
> + efi_status_t status;
> + efi_uintn_t var_size;
> + u16 trial_state_ctr;
> + u32 nimages, active_bank, var_attributes, active_idx;
> + struct fwu_mdata *mdata = NULL;
> + struct fwu_image_entry *img_entry;
> + struct fwu_image_bank_info *img_bank_info;
> +
> + ret = fwu_get_mdata(&mdata);
> + if (ret < 0)
Isn't it easier to have if (ret) here?
> + return ret;
> +
> + ret = 0;
Then you can remove this and the whole ret handling below is weird.
> + nimages = CONFIG_FWU_NUM_IMAGES_PER_BANK;
> + active_bank = mdata->active_index;
> + img_entry = &mdata->img_entry[0];
> + for (i = 0; i < nimages; i++) {
> + img_bank_info = &img_entry[i].img_bank_info[active_bank];
> + if (!img_bank_info->accepted) {
> + trial_state = 1;
> + break;
> + }
> + }
> +
> + if (trial_state) {
> + var_size = (efi_uintn_t)sizeof(trial_state_ctr);
> + log_info("System booting in Trial State\n");
> + var_attributes = EFI_VARIABLE_NON_VOLATILE |
> + EFI_VARIABLE_BOOTSERVICE_ACCESS;
> + status = efi_get_variable_int(L"TrialStateCtr",
> + &efi_global_variable_guid,
> + &var_attributes,
> + &var_size, &trial_state_ctr,
> + NULL);
> + if (status != EFI_SUCCESS) {
> + log_err("Unable to read TrialStateCtr variable\n");
> + ret = -1;
Any reason not to use standard return macros? The same I see below too.
> + goto out;
> + }
> +
> + ++trial_state_ctr;
> + if (trial_state_ctr > CONFIG_FWU_TRIAL_STATE_CNT) {
> + log_info("Trial State count exceeded. Revert back to
> previous_active_index\n");
> + active_idx = mdata->active_index;
> + ret = fwu_revert_boot_index();
> + if (ret < 0) {
I would use if (ret) here.
> + log_err("Unable to revert active_index\n");
> + goto out;
> + }
> +
> + trial_state_ctr = 0;
> + status = efi_set_variable_int(L"TrialStateCtr",
> +
> &efi_global_variable_guid,
> + var_attributes,
> + 0,
> + &trial_state_ctr,
> false);
> + if (status != EFI_SUCCESS) {
> + log_err("Unable to clear TrialStateCtr
> variable\n");
> + ret = -1;
> + goto out;
> + }
> + } else {
> + status = efi_set_variable_int(L"TrialStateCtr",
> +
> &efi_global_variable_guid,
> + var_attributes,
> + var_size,
> + &trial_state_ctr,
> false);
> + if (status != EFI_SUCCESS) {
> + log_err("Unable to increment TrialStateCtr
> variable\n");
> + ret = -1;
> + goto out;
> + } else {
> + ret = 0;
Why do you need this? ret should be 0 when you get here.
> + }
> + }
> + } else {
> + trial_state_ctr = 0;
> + ret = 0;
the same here. You have ret=0 above that's why I think this is just an
additional line here.
> + status = efi_set_variable_int(L"TrialStateCtr",
> + &efi_global_variable_guid,
> + 0,
> + 0, &trial_state_ctr,
> + NULL);
> + }
> +
> +out:
> + free(mdata);
> + return ret;
> +}
> +
> +u8 fwu_update_checks_pass(void)
> +{
> + return !trial_state && boottime_check;
> +}
> +
> +int fwu_boottime_checks(void)
> +{
> + int ret;
> + struct udevice *dev;
> + u32 boot_idx, active_idx;
> +
> + if (uclass_get_device(UCLASS_FWU_MDATA, 0, &dev) || !dev) {
> + log_err("FWU Metadata device not found\n");
> + boottime_check = 0;
All these boottime_check initialization to 0 seems to me useless.
> + return 0;
> + }
> +
> + ret = fwu_mdata_check();
> + if (ret < 0) {
up to you but I would also use if (ret) here.
> + boottime_check = 0;
It is zero already when you get here that's why all these = 0 lines
should be IMHO removed.
> + return 0;
> + }
> +
> + /*
> + * Get the Boot Index, i.e. the bank from
> + * which the platform has booted. This value
> + * gets passed from the ealier stage bootloader
> + * which booted u-boot, e.g. tf-a. If the
> + * boot index is not the same as the
> + * active_index read from the FWU metadata,
> + * update the active_index.
> + */
> + fwu_plat_get_bootidx(&boot_idx);
> + if (boot_idx >= CONFIG_FWU_NUM_BANKS) {
> + log_err("Received incorrect value of boot_index\n");
> + boottime_check = 0;
ditto.
> + return 0;
> + }
> +
> + ret = fwu_get_active_index(&active_idx);
> + if (ret < 0) {
ditto.
> + log_err("Unable to read active_index\n");
> + boottime_check = 0;
ditto.
> + return 0;
> + }
> +
> + if (boot_idx != active_idx) {
> + log_info("Boot idx %u is not matching active idx %u, changing
> active_idx\n",
> + boot_idx, active_idx);
> + ret = fwu_update_active_index(boot_idx);
> + if (ret < 0)
ditto.
> + boottime_check = 0;
ditto
> + else
> + boottime_check = 1;
> +
> + return 0;
> + }
> +
> + ret = fwu_trial_state_check();
> + if (ret < 0)
ditto
> + boottime_check = 0;
ditto.
> + else
> + boottime_check = 1;
> +
> + return 0;
> +}
> --
> 2.17.1
>
Thanks,
Michal
--
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Xilinx Microblaze
Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs
U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal SoCs
