[PATCH v2 15/16] ARM: tegra30: implement BCT patching

Simon Glass sjg at chromium.org
Fri Feb 3 03:15:40 CET 2023


Hi Svyatoslav,

On Thu, 2 Feb 2023 at 11:23, Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
>
> From: Ramin Khonsari <raminterex at yahoo.com>
>
> This function allows updating bootloader from u-boot
> on production devices without need in host PC.
>
> Be aware! It works only with re-crypted BCT.
>
> Tested-by: Andreas Westman Dorcsak <hedmoo at yahoo.com> # ASUS TF T30
> Tested-by: Svyatoslav Ryhel <clamor95 at gmail.com> # LG P895 T30
> Signed-off-by: Ramin Khonsari <raminterex at yahoo.com>
> Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
> ---
>  arch/arm/mach-tegra/Kconfig          | 10 ++++
>  arch/arm/mach-tegra/tegra30/Makefile |  1 +
>  arch/arm/mach-tegra/tegra30/bct.c    | 78 ++++++++++++++++++++++++++++
>  arch/arm/mach-tegra/tegra30/bct.h    | 42 +++++++++++++++
>  4 files changed, 131 insertions(+)
>  create mode 100644 arch/arm/mach-tegra/tegra30/bct.c
>  create mode 100644 arch/arm/mach-tegra/tegra30/bct.h

Please add something to doc/ about this.

>
> diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
> index 5b0cd92d9e..922e57726f 100644
> --- a/arch/arm/mach-tegra/Kconfig
> +++ b/arch/arm/mach-tegra/Kconfig
> @@ -229,4 +229,14 @@ config CMD_ENTERRCM
>           for mechanical button actuators, or hooking up relays/... to the
>           button.
>
> +config CMD_EBTUPDATE
> +       bool "Enable 'ebtupdate' command"
> +       depends on TEGRA30
> +       select TEGRA_CRYPTO
> +       default n

That is always the default so you can drop this line

> +       help
> +         Updating u-boot from within u-boot in rather complex or even
> +         impossible on production devices. To make it easier procedure of
> +         re-cryption was created. If your device was re-crypted choose Y.
> +
>  endif
> diff --git a/arch/arm/mach-tegra/tegra30/Makefile b/arch/arm/mach-tegra/tegra30/Makefile
> index 9f170576e7..28dd486d8d 100644
> --- a/arch/arm/mach-tegra/tegra30/Makefile
> +++ b/arch/arm/mach-tegra/tegra30/Makefile
> @@ -3,5 +3,6 @@
>  # Copyright (c) 2010-2012, NVIDIA CORPORATION.  All rights reserved.
>
>  obj-$(CONFIG_SPL_BUILD) += cpu.o
> +obj-$(CONFIG_$(SPL_)CMD_EBTUPDATE) += bct.o
>
>  obj-y  += clock.o funcmux.o pinmux.o
> diff --git a/arch/arm/mach-tegra/tegra30/bct.c b/arch/arm/mach-tegra/tegra30/bct.c
> new file mode 100644
> index 0000000000..c26338e263
> --- /dev/null
> +++ b/arch/arm/mach-tegra/tegra30/bct.c
> @@ -0,0 +1,78 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2022, Ramin <raminterex at yahoo.com>
> + * Copyright (c) 2022, Svyatoslav Ryhel <clamor95 at gmail.com>
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <log.h>
> +#include <asm/arch-tegra/crypto.h>
> +#include "bct.h"
> +#include "uboot_aes.h"
> +
> +/*
> + * \param bct          boot config table start in RAM
> + * \param ect          bootloader start in RAM
> + * \param ebt_size     bootloader file size in bytes

Returns ?

> + */
> +static int bct_patch(u8 *bct, u8 *ebt, u32 ebt_size)
> +{
> +       struct nvboot_config_table *bct_tbl = NULL;
> +       u8 ebt_hash[AES128_KEY_LENGTH] = { 0 };
> +       u8 sbk[AES128_KEY_LENGTH] = { 0 };
> +       u8 *bct_hash = bct;
> +       int ret;
> +
> +       bct += BCT_HASH;
> +
> +       memcpy(sbk, (u8 *)(bct + BCT_LENGTH),
> +              NVBOOT_CMAC_AES_HASH_LENGTH * 4);
> +
> +       ret = decrypt_data_block(bct, BCT_LENGTH, sbk);
> +       if (ret)
> +               return 1;
> +
> +       ebt_size = roundup(ebt_size, EBT_ALIGNMENT);
> +
> +       ret = encrypt_data_block(ebt, ebt_size, sbk);
> +       if (ret)
> +               return 1;
> +
> +       ret = sign_enc_data_block(ebt, ebt_size, ebt_hash, sbk);
> +       if (ret)
> +               return 1;
> +
> +       bct_tbl = (struct nvboot_config_table *)bct;
> +
> +       memcpy((u8 *)&bct_tbl->bootloader[0].crypto_hash,
> +              ebt_hash, NVBOOT_CMAC_AES_HASH_LENGTH * 4);
> +       bct_tbl->bootloader[0].entry_point = CONFIG_SPL_TEXT_BASE;
> +       bct_tbl->bootloader[0].load_addr = CONFIG_SPL_TEXT_BASE;
> +       bct_tbl->bootloader[0].length = ebt_size;
> +
> +       ret = encrypt_data_block(bct, BCT_LENGTH, sbk);
> +       if (ret)
> +               return 1;
> +
> +       ret = sign_enc_data_block(bct, BCT_LENGTH, bct_hash, sbk);
> +       if (ret)
> +               return 1;
> +
> +       return 0;
> +}
> +
> +static int do_ebtupdate(struct cmd_tbl *cmdtp, int flag, int argc,
> +                       char *const argv[])
> +{
> +       u32 bct_addr = hextoul(argv[1], NULL);
> +       u32 ebt_addr = hextoul(argv[2], NULL);
> +       u32 ebt_size = hextoul(argv[3], NULL);
> +
> +       return bct_patch((u8 *)bct_addr, (u8 *)ebt_addr, ebt_size);
> +}
> +
> +U_BOOT_CMD(ebtupdate,  4,      0,      do_ebtupdate,
> +          "update bootloader on re-crypted Tegra30 devices",
> +          ""

Please add doc/usage/cmd file

> +);
> diff --git a/arch/arm/mach-tegra/tegra30/bct.h b/arch/arm/mach-tegra/tegra30/bct.h
> new file mode 100644
> index 0000000000..9797384da3
> --- /dev/null
> +++ b/arch/arm/mach-tegra/tegra30/bct.h
> @@ -0,0 +1,42 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +
> +#ifndef _BCT_H_
> +#define _BCT_H_
> +
> +/*
> + * Defines the BCT parametres for T30
> + */
> +#define BCT_LENGTH             0x17E0
> +#define BCT_HASH               0x10
> +#define EBT_ALIGNMENT          0x10
> +
> +/*
> + * Defines the CMAC-AES-128 hash length in 32 bit words. (128 bits = 4 words)
> + */
> +#define NVBOOT_CMAC_AES_HASH_LENGTH            4
> +
> +/*
> + * Defines the maximum number of bootloader descriptions in the BCT.
> + */
> +#define NVBOOT_MAX_BOOTLOADERS                 4
> +
> +struct nv_bootloader_info {
> +       u32 version;
> +       u32 start_blk;
> +       u32 start_page;
> +       u32 length;
> +       u32 load_addr;
> +       u32 entry_point;
> +       u32 attribute;
> +       u32 crypto_hash[NVBOOT_CMAC_AES_HASH_LENGTH];
> +};
> +
> +struct nvboot_config_table {
> +       u32 unused0[4];
> +       u32 boot_data_version;
> +       u32 unused1[972];
> +       struct nv_bootloader_info bootloader[NVBOOT_MAX_BOOTLOADERS];
> +       u32 unused2[508];
> +};
> +
> +#endif /* _BCT_H_ */
> --
> 2.37.2
>

Regards,
Simon


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