[U-Boot] [PATCH v3 1/6] x86: baytrail: Add fsp-header verification for secure boot FSP

Bin Meng
2017-11-21T15:01:08Z

Hi Anatolij,

On Fri, Nov 17, 2017 at 9:13 AM, Anatolij Gustschin <agust@denx.de> wrote:
> From: Markus Valentin <mv@denx.de>
>
> Introduce a new Kconfig variable for secure boot on Bay Trail based
> platforms. If this variable is set, the build process tries to use
> fsp-sb.bin instead of fsp.bin (-sb is the secure boot enabled FSP).
>
> Also check the two FSP headers against each other and print if secure
> boot is enabled or not.
>
> Signed-off-by: Markus Valentin <mv@denx.de>
> Signed-off-by: Anatolij Gustschin <agust@denx.de>
> ---
> Changes in v3:
> - move BAYTRAIL_SECURE_BOOT to arch/x86/cpu/baytrail/Kconfig
> - Kconfig help text improvements
> - fix crownbay build breakage
>
> Changes in v2:
> - use if (IS_ENABLED(CONFIG_*)) instead of #ifdef
> - s/SB/Secure Boot/
> - minor Kconfig help cleanup
>
> arch/x86/Kconfig | 3 ++-
> arch/x86/cpu/baytrail/Kconfig | 10 ++++++++++
> arch/x86/include/asm/fsp/fsp_support.h | 2 ++
> arch/x86/lib/fsp/fsp_support.c | 24 ++++++++++++++++++++++++
> 4 files changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 98c56ad7dc..6755e92748 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -350,7 +350,8 @@ config HAVE_FSP
> config FSP_FILE
> string "Firmware Support Package binary filename"
> depends on HAVE_FSP
> - default "fsp.bin"
> + default "fsp.bin" if !BAYTRAIL_SECURE_BOOT
> + default "fsp-sb.bin" if BAYTRAIL_SECURE_BOOT

Since this Kconfig is generic to all x86, can we introduce a generic
name here, something like:

default "fsp-sb.bin" if SECURE_BOOT

Then in the arch/x86/cpu/baytrail/Kconfig, we can have:

config BAYTRAIL_SECURE_BOOT
depends on HAVE_FSP
depends on SECURE_BOOT
default y if SECURE_BOOT

Does U-Boot have any generic Kconfig option for secure boot?

> help
> The filename of the file to use as Firmware Support Package binary
> in the board directory.
> diff --git a/arch/x86/cpu/baytrail/Kconfig b/arch/x86/cpu/baytrail/Kconfig
> index 1d876b1927..ff244fcd68 100644
> --- a/arch/x86/cpu/baytrail/Kconfig
> +++ b/arch/x86/cpu/baytrail/Kconfig
> @@ -39,4 +39,14 @@ config DEBUG_UART
> bool
> select DEBUG_UART_BOARD_INIT
>
> +config BAYTRAIL_SECURE_BOOT
> + bool "Enable Secure Boot on Bay Trail"
> + depends on HAVE_FSP
> + default n
> + help
> + Use the secure boot feature of the Bay Trail platform. This switch
> + enables the usage of the secure-boot enabled fsp.bin (fsp-sb.bin).
> + For your board you need to provide this yourself. You can reconfigure
> + your FSP with the Intel BCT tool to enable secure boot.
> +
> endif
> diff --git a/arch/x86/include/asm/fsp/fsp_support.h b/arch/x86/include/asm/fsp/fsp_support.h
> index df3add008c..124a4148a0 100644
> --- a/arch/x86/include/asm/fsp/fsp_support.h
> +++ b/arch/x86/include/asm/fsp/fsp_support.h
> @@ -22,6 +22,8 @@
> #define FSP_LOWMEM_BASE 0x100000UL
> #define FSP_HIGHMEM_BASE 0x100000000ULL
> #define UPD_TERMINATOR 0x55AA
> +#define FSP_FIRST_HEADER_OFFSET 0x94
> +#define FSP_SECOND_HEADER_OFFSET 0x20494
>
>
> /**
> diff --git a/arch/x86/lib/fsp/fsp_support.c b/arch/x86/lib/fsp/fsp_support.c
> index e0c49be635..d79a6e900a 100644
> --- a/arch/x86/lib/fsp/fsp_support.c
> +++ b/arch/x86/lib/fsp/fsp_support.c
> @@ -97,6 +97,8 @@ void fsp_continue(u32 status, void *hob_list)
> fsp_init_done(hob_list);
> }
>
> +#define SB_PRFX "Secure Boot:"
> +
> void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
> {
> struct fsp_config_data config_data;
> @@ -116,6 +118,14 @@ void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
> panic("Invalid FSP header");
> }
>
> + if (IS_ENABLED(CONFIG_BAYTRAIL_SECURE_BOOT)) {
> + /* Compare primary and secondary header */
> + if (memcmp((void *)(CONFIG_FSP_ADDR + FSP_FIRST_HEADER_OFFSET),
> + (void *)(CONFIG_FSP_ADDR + FSP_SECOND_HEADER_OFFSET),
> + fsp_hdr->hdr_len))
> + panic("%s 1st & 2nd FSP headers don't match", SB_PRFX);
> + }
> +
> config_data.common.fsp_hdr = fsp_hdr;
> config_data.common.stack_top = stack_top;
> config_data.common.boot_mode = boot_mode;
> @@ -130,6 +140,20 @@ void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
>
> fsp_upd = &config_data.fsp_upd;
>
> + /*
> + * On some platforms there is no 'enable_secure_boot' field
> + * in VPD region struct, so we have to use ifdef here.
> + */
> + #ifdef CONFIG_BAYTRAIL_SECURE_BOOT
> + /*
> + * If the enable secure boot flag is not 1, secure boot has not
> + * been activated in the FSP which results in the TXE-Engine not
> + * getting loaded
> + */
> + printf("FSP: Secure Boot %sabled\n",
> + fsp_vpd->enable_secure_boot == 1 ? "en" : "dis");
> + #endif
> +

Can we introduce some APIs like fsp_secure_boot_check() and move the
above 2 blocks into baytrail directory that implements the API?

> /* Copy default data from Flash */
> memcpy(fsp_upd, (void *)(fsp_hdr->img_base + fsp_vpd->upd_offset),
> sizeof(struct upd_region));
> --

Regards,
Bin