diff --git a/src/soc/intel/xeon_sp/cpx/acpi.c b/src/soc/intel/xeon_sp/cpx/acpi.c
index a1ebc4ae92..8d3e86a10b 100644
--- a/src/soc/intel/xeon_sp/cpx/acpi.c
+++ b/src/soc/intel/xeon_sp/cpx/acpi.c
@@ -130,13 +130,18 @@ unsigned long acpi_fill_madt(unsigned long current)
 
 void acpi_fill_fadt(acpi_fadt_t *fadt)
 {
-
 	const uint16_t pmbase = ACPI_BASE_ADDRESS;
 
 	fadt->header.revision = get_acpi_table_revision(FADT);
 
 	fadt->sci_int = acpi_sci_irq();
 
+	if (permanent_smi_handler()) {
+		fadt->smi_cmd = APM_CNT;
+		fadt->acpi_enable = APM_CNT_ACPI_ENABLE;
+		fadt->acpi_disable = APM_CNT_ACPI_DISABLE;
+	}
+
 	fadt->pm1a_evt_blk = pmbase + PM1_STS;
 	fadt->pm1a_cnt_blk = pmbase + PM1_CNT;
 
@@ -151,26 +156,29 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->duty_offset = 1;
 	fadt->day_alrm = 0xd;
 
-	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED | ACPI_FADT_C2_MP_SUPPORTED |
+	fadt->flags |= ACPI_FADT_WBINVD | ACPI_FADT_C1_SUPPORTED |
+			ACPI_FADT_C2_MP_SUPPORTED | ACPI_FADT_SLEEP_BUTTON |
+			ACPI_FADT_SEALED_CASE | ACPI_FADT_S4_RTC_WAKE |
 			ACPI_FADT_PLATFORM_CLOCK;
 
 	fadt->x_pm1a_evt_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_pm1a_evt_blk.bit_width = fadt->pm1_evt_len * 8;
 	fadt->x_pm1a_evt_blk.addrl = pmbase + PM1_STS;
+	fadt->x_pm1a_evt_blk.access_size = ACPI_ACCESS_SIZE_WORD_ACCESS;
 
 	fadt->x_pm1a_cnt_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_pm1a_cnt_blk.bit_width = fadt->pm1_cnt_len * 8;
 	fadt->x_pm1a_cnt_blk.addrl = pmbase + PM1_CNT;
+	fadt->x_pm1a_cnt_blk.access_size = ACPI_ACCESS_SIZE_WORD_ACCESS;
 
-	if (permanent_smi_handler()) {
-		fadt->smi_cmd = APM_CNT;
-		fadt->acpi_enable = APM_CNT_ACPI_ENABLE;
-		fadt->acpi_disable = APM_CNT_ACPI_DISABLE;
-	}
-
-	/*  General-Purpose Event Registers */
+	/*
+	 * Windows 10 requires x_gpe0_blk to be set starting with FADT revision 5.
+	 * The bit_width field intentionally overflows here.
+	 * The OSPM can instead use the values in `fadt->gpe0_blk{,_len}`, which
+	 * seems to work fine on Linux 5.0 and Windows 10.
+	 */
 	fadt->x_gpe0_blk.space_id = ACPI_ADDRESS_SPACE_IO;
-	fadt->x_gpe0_blk.bit_width = 64; /* EventStatus + EventEnable */
+	fadt->x_gpe0_blk.bit_width = fadt->gpe0_blk_len * 8;
 	fadt->x_gpe0_blk.bit_offset = 0;
 	fadt->x_gpe0_blk.access_size = ACPI_ACCESS_SIZE_BYTE_ACCESS;
 	fadt->x_gpe0_blk.addrl = fadt->gpe0_blk;
diff --git a/src/soc/intel/xeon_sp/cpx/soc_acpi.c b/src/soc/intel/xeon_sp/cpx/soc_acpi.c
index db1d3d2bd2..d0b82e57db 100644
--- a/src/soc/intel/xeon_sp/cpx/soc_acpi.c
+++ b/src/soc/intel/xeon_sp/cpx/soc_acpi.c
@@ -52,6 +52,13 @@ uint32_t soc_read_sci_irq_select(void)
 	return pci_read_config32(dev, PMC_ACPI_CNT);
 }
 
+void soc_fill_fadt(acpi_fadt_t *fadt)
+{
+	/* Clear flags set by common/block/acpi/acpi.c acpi_fill_fadt() */
+	fadt->flags &=  ~(ACPI_FADT_SLEEP_BUTTON | ACPI_FADT_SEALED_CASE |
+				ACPI_FADT_S4_RTC_WAKE);
+}
+
 /*
  * Currently called in southbridge_inject_dsdt(). Change to soc_southbridge_inject_dsdt()
  * with a call from the common/function or find another way to call this at the correct place