diff --git a/Documentation/drivers/smmstorev2.md b/Documentation/drivers/smmstorev2.md
index cf714835a5..b29ffa886f 100644
--- a/Documentation/drivers/smmstorev2.md
+++ b/Documentation/drivers/smmstorev2.md
@@ -74,19 +74,30 @@ has to read the coreboot table with tag `0x0039`, containing:
 struct lb_smmstorev2 {
 	uint32_t tag;
 	uint32_t size;
-	uint32_t num_blocks;	/* Number of writeable blocks in SMM */
-	uint32_t block_size;	/* Size of a block in byte. Default: 64 KiB */
-	uint32_t mmap_addr;	/* MMIO address of the store for read only access */
-	uint32_t com_buffer;	/* Physical address of the communication buffer */
-	uint32_t com_buffer_size;	/* Size of the communication buffer in byte */
-	uint8_t apm_cmd;	/* The command byte to write to the APM I/O port */
-	uint8_t unused[3];	/* Set to zero */
+	uint32_t num_blocks;		/* Number of writable blocks in SMM */
+	uint32_t block_size;		/* Size of a block in byte. Default: 64 KiB */
+	uint32_t mmap_addr_deprecated;	/* 32-bit MMIO address of the store for read only access.
+					   Prefer 'mmap_addr' for new software.
+					   Zero when the address won't fit into 32-bits. */
+	uint32_t com_buffer;		/* Physical address of the communication buffer */
+	uint32_t com_buffer_size;	/* Size of the communication buffer in bytes */
+	uint8_t apm_cmd;		/* The command byte to write to the APM I/O port */
+	uint8_t unused[3];		/* Set to zero */
+	uint64_t mmap_addr;		/* 64-bit MMIO address of the store for read only access.
+					   Introduced after the initial implementation. Users of
+					   this table must check the 'size' field to detect if its
+					   written out by coreboot. */
 };
 ```
 
 The absence of this coreboot table entry indicates that there's no
 SMMSTOREv2 support.
 
+`mmap_addr` is an optional field added after the initial implementation.
+Users of this table must check the size field to know if it's written by coreboot.
+In case it's not present 'mmap_addr_deprecated' is to be used as the SPI ROM MMIO
+address and it must be below 4 GiB.
+
 ### Blocks
 
 The SMMSTOREv2 splits the SMMSTORE FMAP partition into smaller chunks
diff --git a/src/commonlib/include/commonlib/coreboot_tables.h b/src/commonlib/include/commonlib/coreboot_tables.h
index 78dbe8ef4c..7860a413ce 100644
--- a/src/commonlib/include/commonlib/coreboot_tables.h
+++ b/src/commonlib/include/commonlib/coreboot_tables.h
@@ -539,11 +539,17 @@ struct lb_smmstorev2 {
 	uint32_t size;
 	uint32_t num_blocks;		/* Number of writable blocks in SMM */
 	uint32_t block_size;		/* Size of a block in byte. Default: 64 KiB */
-	uint32_t mmap_addr;		/* MMIO address of the store for read only access */
+	uint32_t mmap_addr_deprecated;	/* 32-bit MMIO address of the store for read only access.
+					   Prefer 'mmap_addr' for new software.
+					   Zero when the address won't fit into 32-bits. */
 	uint32_t com_buffer;		/* Physical address of the communication buffer */
 	uint32_t com_buffer_size;	/* Size of the communication buffer in bytes */
 	uint8_t apm_cmd;		/* The command byte to write to the APM I/O port */
 	uint8_t unused[3];		/* Set to zero */
+	uint64_t mmap_addr;		/* 64-bit MMIO address of the store for read only access.
+					   Introduced after the initial implementation. Users of
+					   this table must check the 'size' field to detect if its
+					   written out by coreboot. */
 };
 
 enum lb_tpm_ppi_tpm_version {
diff --git a/src/drivers/smmstore/ramstage.c b/src/drivers/smmstore/ramstage.c
index 1cbf9fb28a..507678754c 100644
--- a/src/drivers/smmstore/ramstage.c
+++ b/src/drivers/smmstore/ramstage.c
@@ -28,6 +28,10 @@ void lb_smmstorev2(struct lb_header *header)
 	store->size = sizeof(*store);
 	store->com_buffer = (uintptr_t)cbmem_entry_start(e);
 	store->com_buffer_size = cbmem_entry_size(e);
+	if (info.mmap_addr < 4ULL * GiB)
+		store->mmap_addr_deprecated = info.mmap_addr;
+	else
+		store->mmap_addr_deprecated = 0;
 	store->mmap_addr = info.mmap_addr;
 	store->num_blocks = info.num_blocks;
 	store->block_size = info.block_size;
diff --git a/src/include/smmstore.h b/src/include/smmstore.h
index 595fe8b29b..4ee4c55c75 100644
--- a/src/include/smmstore.h
+++ b/src/include/smmstore.h
@@ -69,7 +69,7 @@ struct smmstore_params_init {
 struct smmstore_params_info {
 	uint32_t num_blocks;
 	uint32_t block_size;
-	uint32_t mmap_addr;
+	uint64_t mmap_addr;
 } __packed;
 
 /*