diff --git a/src/mainboard/amd/majolica/Makefile.inc b/src/mainboard/amd/majolica/Makefile.inc
index 7c146cf97e..23e9dd1b5e 100644
--- a/src/mainboard/amd/majolica/Makefile.inc
+++ b/src/mainboard/amd/majolica/Makefile.inc
@@ -3,6 +3,8 @@
 bootblock-y += bootblock.c
 bootblock-y += early_gpio.c
 
+romstage-y += port_descriptors.c
+
 ramstage-y += chromeos.c
 
 APCB_SOURCES = $(MAINBOARD_BLOBS_DIR)/APCB_CZN_D4.bin
diff --git a/src/mainboard/amd/majolica/port_descriptors.c b/src/mainboard/amd/majolica/port_descriptors.c
new file mode 100644
index 0000000000..913e48bb60
--- /dev/null
+++ b/src/mainboard/amd/majolica/port_descriptors.c
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <soc/platform_descriptors.h>
+#include <types.h>
+
+static const fsp_dxio_descriptor majolica_czn_dxio_descriptors[] = {
+};
+
+static const fsp_ddi_descriptor majolica_czn_ddi_descriptors[] = {
+};
+
+void mainboard_get_dxio_ddi_descriptors(
+		const fsp_dxio_descriptor **dxio_descs, size_t *dxio_num,
+		const fsp_ddi_descriptor **ddi_descs, size_t *ddi_num)
+{
+	*dxio_descs = majolica_czn_dxio_descriptors;
+	*dxio_num = ARRAY_SIZE(majolica_czn_dxio_descriptors);
+	*ddi_descs = majolica_czn_ddi_descriptors;
+	*ddi_num = ARRAY_SIZE(majolica_czn_ddi_descriptors);
+}
diff --git a/src/mainboard/google/guybrush/Makefile.inc b/src/mainboard/google/guybrush/Makefile.inc
index 263483fd33..d4eeaf5e56 100644
--- a/src/mainboard/google/guybrush/Makefile.inc
+++ b/src/mainboard/google/guybrush/Makefile.inc
@@ -10,6 +10,8 @@ else
 $(info APCB sources not found.  Skipping APCB.)
 endif
 
+romstage-y += port_descriptors.c
+
 ramstage-y += mainboard.c
 ramstage-y += ec.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
diff --git a/src/mainboard/google/guybrush/port_descriptors.c b/src/mainboard/google/guybrush/port_descriptors.c
new file mode 100644
index 0000000000..d407fe9302
--- /dev/null
+++ b/src/mainboard/google/guybrush/port_descriptors.c
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <soc/platform_descriptors.h>
+#include <types.h>
+
+static const fsp_dxio_descriptor guybrush_czn_dxio_descriptors[] = {
+};
+
+static const fsp_ddi_descriptor guybrush_czn_ddi_descriptors[] = {
+};
+
+void mainboard_get_dxio_ddi_descriptors(
+		const fsp_dxio_descriptor **dxio_descs, size_t *dxio_num,
+		const fsp_ddi_descriptor **ddi_descs, size_t *ddi_num)
+{
+	*dxio_descs = guybrush_czn_dxio_descriptors;
+	*dxio_num = ARRAY_SIZE(guybrush_czn_dxio_descriptors);
+	*ddi_descs = guybrush_czn_ddi_descriptors;
+	*ddi_num = ARRAY_SIZE(guybrush_czn_ddi_descriptors);
+}
diff --git a/src/mainboard/google/mancomb/Makefile.inc b/src/mainboard/google/mancomb/Makefile.inc
index ccf90559c8..21e71d7a44 100644
--- a/src/mainboard/google/mancomb/Makefile.inc
+++ b/src/mainboard/google/mancomb/Makefile.inc
@@ -4,6 +4,8 @@ bootblock-y += bootblock.c
 
 verstage-y += verstage.c
 
+romstage-y += port_descriptors.c
+
 ramstage-y += ec.c
 ramstage-y += mainboard.c
 ramstage-$(CONFIG_CHROMEOS) += chromeos.c
diff --git a/src/mainboard/google/mancomb/port_descriptors.c b/src/mainboard/google/mancomb/port_descriptors.c
new file mode 100644
index 0000000000..8a761fecab
--- /dev/null
+++ b/src/mainboard/google/mancomb/port_descriptors.c
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <soc/platform_descriptors.h>
+#include <types.h>
+
+static const fsp_dxio_descriptor mancomb_czn_dxio_descriptors[] = {
+};
+
+static const fsp_ddi_descriptor mancomb_czn_ddi_descriptors[] = {
+};
+
+void mainboard_get_dxio_ddi_descriptors(
+		const fsp_dxio_descriptor **dxio_descs, size_t *dxio_num,
+		const fsp_ddi_descriptor **ddi_descs, size_t *ddi_num)
+{
+	*dxio_descs = mancomb_czn_dxio_descriptors;
+	*dxio_num = ARRAY_SIZE(mancomb_czn_dxio_descriptors);
+	*ddi_descs = mancomb_czn_ddi_descriptors;
+	*ddi_num = ARRAY_SIZE(mancomb_czn_ddi_descriptors);
+}
diff --git a/src/soc/amd/cezanne/fsp_m_params.c b/src/soc/amd/cezanne/fsp_m_params.c
index 083a82d90c..f24b601c70 100644
--- a/src/soc/amd/cezanne/fsp_m_params.c
+++ b/src/soc/amd/cezanne/fsp_m_params.c
@@ -2,8 +2,51 @@
 
 #include <amdblocks/apob_cache.h>
 #include <amdblocks/memmap.h>
+#include <assert.h>
 #include <console/uart.h>
 #include <fsp/api.h>
+#include <soc/platform_descriptors.h>
+#include <string.h>
+#include <types.h>
+
+static void fill_dxio_descriptors(FSP_M_CONFIG *mcfg,
+			const fsp_dxio_descriptor *descs, size_t num)
+{
+	size_t i;
+
+	ASSERT_MSG(num <= FSPM_UPD_DXIO_DESCRIPTOR_COUNT,
+			"Too many DXIO descriptors provided.");
+
+	for (i = 0; i < num; i++) {
+		memcpy(mcfg->dxio_descriptor[i], &descs[i], sizeof(mcfg->dxio_descriptor[0]));
+	}
+}
+
+static void fill_ddi_descriptors(FSP_M_CONFIG *mcfg,
+			const fsp_ddi_descriptor *descs, size_t num)
+{
+	size_t i;
+
+	ASSERT_MSG(num <= FSPM_UPD_DDI_DESCRIPTOR_COUNT,
+			"Too many DDI descriptors provided.");
+
+	for (i = 0; i < num; i++) {
+		memcpy(&mcfg->ddi_descriptor[i], &descs[i], sizeof(mcfg->ddi_descriptor[0]));
+	}
+}
+
+static void fsp_fill_pcie_ddi_descriptors(FSP_M_CONFIG *mcfg)
+{
+	const fsp_dxio_descriptor *fsp_dxio;
+	const fsp_ddi_descriptor *fsp_ddi;
+	size_t num_dxio;
+	size_t num_ddi;
+
+	mainboard_get_dxio_ddi_descriptors(&fsp_dxio, &num_dxio,
+						&fsp_ddi, &num_ddi);
+	fill_dxio_descriptors(mcfg, fsp_dxio, num_dxio);
+	fill_ddi_descriptors(mcfg, fsp_ddi, num_ddi);
+}
 
 void platform_fsp_memory_init_params_cb(FSPM_UPD *mupd, uint32_t version)
 {
@@ -18,4 +61,6 @@ void platform_fsp_memory_init_params_cb(FSPM_UPD *mupd, uint32_t version)
 	mcfg->serial_port_use_mmio = CONFIG(DRIVERS_UART_8250MEM);
 	mcfg->serial_port_baudrate = get_uart_baudrate();
 	mcfg->serial_port_refclk = uart_platform_refclk();
+
+	fsp_fill_pcie_ddi_descriptors(mcfg);
 }
diff --git a/src/soc/amd/cezanne/include/soc/platform_descriptors.h b/src/soc/amd/cezanne/include/soc/platform_descriptors.h
new file mode 100644
index 0000000000..d68cd7fab9
--- /dev/null
+++ b/src/soc/amd/cezanne/include/soc/platform_descriptors.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef AMD_PICASSO_PLATFORM_DESCRIPTORS_H
+#define AMD_PICASSO_PLATFORM_DESCRIPTORS_H
+
+#include <types.h>
+#include <platform_descriptors.h>
+#include <FspmUpd.h>
+
+/* Mainboard callback to obtain DXI/PCIe and DDI descriptors. */
+void mainboard_get_dxio_ddi_descriptors(
+		const fsp_dxio_descriptor **dxio_descs, size_t *dxio_num,
+		const fsp_ddi_descriptor **ddi_descs, size_t *ddi_num);
+
+#endif /* AMD_PICASSO_PLATFORM_DESCRIPTORS_H */