On Wed, Apr 19, 2017 at 9:33 PM, Jan Kiszka <jan.kiszka@xxxxxxxxxxx> wrote:
> The firmware for Quark X102x prepends a security header to the capsule
> which is needed to support the mandatory secure boot on this processor.
> The header can be detected by checking for the "_CSH" signature and -
> to avoid any GUID conflict - validating its size field to contain the
> expected value. Then we need to look for the EFI header right after the
> security header and pass the real header to __efi_capsule_setup_info.
>
> To be minimal invasive and maximal safe, the quirk version of
> efi_capsule_identify_image is only effective on Quark processors.
>
FWIW:
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
> arch/x86/platform/efi/quirks.c | 137 +++++++++++++++++++++++++++++++++++++++++
> drivers/firmware/efi/Kconfig | 9 +++
> 2 files changed, 146 insertions(+)
>
> diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
> index cdfe8c628959..8f41a75f8604 100644
> --- a/arch/x86/platform/efi/quirks.c
> +++ b/arch/x86/platform/efi/quirks.c
> @@ -13,12 +13,66 @@
> #include <linux/dmi.h>
> #include <asm/efi.h>
> #include <asm/uv/uv.h>
> +#include <asm/cpu_device_id.h>
>
> #define EFI_MIN_RESERVE 5120
>
> #define EFI_DUMMY_GUID \
> EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
>
> +#define QUARK_CSH_SIGNATURE 0x5f435348 /* _CSH */
> +#define QUARK_SECURITY_HEADER_SIZE 0x400
> +
> +/*
> + * Header prepended to the standard EFI capsule on Quark systems the are based
> + * on Intel firmware BSP.
> + * @csh_signature: Unique identifier to sanity check signed module
> + * presence ("_CSH").
> + * @version: Current version of CSH used. Should be one for Quark A0.
> + * @modulesize: Size of the entire module including the module header
> + * and payload.
> + * @security_version_number_index: Index of SVN to use for validation of signed
> + * module.
> + * @security_version_number: Used to prevent against roll back of modules.
> + * @rsvd_module_id: Currently unused for Clanton (Quark).
> + * @rsvd_module_vendor: Vendor Identifier. For Intel products value is
> + * 0x00008086.
> + * @rsvd_date: BCD representation of build date as yyyymmdd, where
> + * yyyy=4 digit year, mm=1-12, dd=1-31.
> + * @headersize: Total length of the header including including any
> + * padding optionally added by the signing tool.
> + * @hash_algo: What Hash is used in the module signing.
> + * @cryp_algo: What Crypto is used in the module signing.
> + * @keysize: Total length of the key data including including any
> + * padding optionally added by the signing tool.
> + * @signaturesize: Total length of the signature including including any
> + * padding optionally added by the signing tool.
> + * @rsvd_next_header: 32-bit pointer to the next Secure Boot Module in the
> + * chain, if there is a next header.
> + * @rsvd: Reserved, padding structure to required size.
> + *
> + * See also QuartSecurityHeader_t in
> + * Quark_EDKII_v1.2.1.1/QuarkPlatformPkg/Include/QuarkBootRom.h
> + * from https://downloadcenter.intel.com/download/23197/Intel-Quark-SoC-X1000-Board-Support-Package-BSP
> + */
> +struct quark_security_header {
> + u32 csh_signature;
> + u32 version;
> + u32 modulesize;
> + u32 security_version_number_index;
> + u32 security_version_number;
> + u32 rsvd_module_id;
> + u32 rsvd_module_vendor;
> + u32 rsvd_date;
> + u32 headersize;
> + u32 hash_algo;
> + u32 cryp_algo;
> + u32 keysize;
> + u32 signaturesize;
> + u32 rsvd_next_header;
> + u32 rsvd[2];
> +};
> +
> static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
>
> static bool efi_no_storage_paranoia;
> @@ -499,3 +553,86 @@ bool efi_poweroff_required(void)
> {
> return acpi_gbl_reduced_hardware || acpi_no_s5;
> }
> +
> +#ifdef CONFIG_EFI_CAPSULE_QUIRK_QUARK_CSH
> +
> +static int qrk_capsule_setup_info(struct capsule_info *cap_info, void **pkbuff,
> + size_t hdr_bytes)
> +{
> + struct quark_security_header *csh = *pkbuff;
> +
> + /* Only process data block that is larger than the security header */
> + if (hdr_bytes < sizeof(struct quark_security_header))
> + return 0;
> +
> + if (csh->csh_signature != QUARK_CSH_SIGNATURE ||
> + csh->headersize != QUARK_SECURITY_HEADER_SIZE)
> + return 1;
> +
> + /* Only process data block if EFI header is included */
> + if (hdr_bytes < QUARK_SECURITY_HEADER_SIZE +
> + sizeof(efi_capsule_header_t))
> + return 0;
> +
> + pr_debug("Quark security header detected\n");
> +
> + if (csh->rsvd_next_header != 0) {
> + pr_err("multiple Quark security headers not supported\n");
> + return -EINVAL;
> + }
> +
> + *pkbuff += csh->headersize;
> + cap_info->total_size = csh->headersize;
> +
> + /*
> + * Update the first page pointer to skip over the CSH header.
> + */
> + cap_info->pages[0] += csh->headersize;
> +
> + return 1;
> +}
> +
> +#define ICPU(family, model, quirk_handler) \
> + { X86_VENDOR_INTEL, family, model, X86_FEATURE_ANY, \
> + (unsigned long)&quirk_handler }
> +
> +static const struct x86_cpu_id efi_capsule_quirk_ids[] = {
> + ICPU(5, 9, qrk_capsule_setup_info), /* Intel Quark X1000 */
> + { }
> +};
> +
> +int efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
> + size_t hdr_bytes)
> +{
> + int (*quirk_handler)(struct capsule_info *, void **, size_t);
> + const struct x86_cpu_id *id;
> + int ret;
> +
> + if (hdr_bytes < sizeof(efi_capsule_header_t))
> + return 0;
> +
> + cap_info->total_size = 0;
> +
> + id = x86_match_cpu(efi_capsule_quirk_ids);
> + if (id) {
> + /*
> + * The quirk handler is supposed to return
> + * - a value > 0 if the setup should continue, after advancing
> + * kbuff as needed
> + * - 0 if not enough hdr_bytes are available yet
> + * - a negative error code otherwise
> + */
> + quirk_handler = (typeof(quirk_handler))id->driver_data;
> + ret = quirk_handler(cap_info, &kbuff, hdr_bytes);
> + if (ret <= 0)
> + return ret;
> + }
> +
> + memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
> +
> + cap_info->total_size += cap_info->header.imagesize;
> +
> + return __efi_capsule_setup_info(cap_info);
> +}
> +
> +#endif
> diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
> index 2e78b0b96d74..394db40ed374 100644
> --- a/drivers/firmware/efi/Kconfig
> +++ b/drivers/firmware/efi/Kconfig
> @@ -112,6 +112,15 @@ config EFI_CAPSULE_LOADER
>
> Most users should say N.
>
> +config EFI_CAPSULE_QUIRK_QUARK_CSH
> + boolean "Add support for Quark capsules with non-standard headers"
> + depends on X86 && !64BIT
> + select EFI_CAPSULE_LOADER
> + default y
> + help
> + Add support for processing Quark X1000 EFI capsules, whose header
> + layout deviates from the layout mandated by the UEFI specification.
> +
> config EFI_TEST
> tristate "EFI Runtime Service Tests Support"
> depends on EFI
> --
> 2.12.0
>
--
With Best Regards,
Andy Shevchenko
--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
