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 image displacement in cap_info.
To be minimal invasive and maximal safe, the quirk version of
efi_capsule_identify_image is only effective on Quark processors.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
arch/x86/platform/efi/quirks.c | 95 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 30031d5..7f16295 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;
@@ -495,3 +549,44 @@ bool efi_poweroff_required(void)
{
return acpi_gbl_reduced_hardware || acpi_no_s5;
}
+
+static const struct x86_cpu_id quark_ids[] = {
+ { X86_VENDOR_INTEL, 5, 9 }, /* Intel Quark X1000 */
+ { }
+};
+
+int efi_capsule_identify_image(struct efi_capsule_info *cap_info, void *header,
+ size_t hdr_bytes)
+{
+ struct quark_security_header *csh = header;
+
+ if (!x86_match_cpu(quark_ids))
+ return __efi_capsule_identify_image(cap_info, header,
+ hdr_bytes);
+
+ /* 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 __efi_capsule_identify_image(cap_info, header,
+ hdr_bytes);
+
+ /* 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;
+ }
+
+ cap_info->total_size = csh->modulesize;
+ cap_info->efi_hdr_displacement = csh->headersize;
+
+ return 1;
+}
--
2.10.2
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