diff --git a/arch/x86/include/asm/cb_sysinfo.h b/arch/x86/include/asm/cb_sysinfo.h
index 6b26614..2c78b22 100644
--- a/arch/x86/include/asm/cb_sysinfo.h
+++ b/arch/x86/include/asm/cb_sysinfo.h
@@ -16,6 +16,8 @@
 #define SYSINFO_MAX_GPIOS	8
 /* Up to 10 MAC addresses */
 #define SYSINFO_MAX_MACS 10
+/* Track the first 32 unimplemented tags */
+#define SYSINFO_MAX_UNIMPL	32
 
 /**
  * struct sysinfo_t - Information passed to U-Boot from coreboot
@@ -134,6 +136,8 @@
  * @chromeos_vpd: Chromium OS Vital Product Data region, typically NULL, meaning
  *	not used
  * @rsdp: Pointer to ACPI RSDP table
+ * @unimpl_count: Number of entries in unimpl_map[]
+ * @unimpl: List of unimplemented IDs (bottom 8 bits only)
  */
 struct sysinfo_t {
 	unsigned int cpu_khz;
@@ -213,6 +217,8 @@
 	u32 mtc_size;
 	void	*chromeos_vpd;
 	void *rsdp;
+	u32 unimpl_count;
+	u8 unimpl[SYSINFO_MAX_UNIMPL];
 };
 
 extern struct sysinfo_t lib_sysinfo;