diff --git a/src/soc/amd/picasso/acpi/sb_pci0_fch.asl b/src/soc/amd/picasso/acpi/sb_pci0_fch.asl
index 27c4661..7488b55 100644
--- a/src/soc/amd/picasso/acpi/sb_pci0_fch.asl
+++ b/src/soc/amd/picasso/acpi/sb_pci0_fch.asl
@@ -101,6 +101,11 @@
 	Subtract(Local0, TOM1, Local0)
 	Store(Local0, MM1L)
 
+	CreateWordField(CRES, ^PSB0._MAX, BMAX)
+	CreateWordField(CRES, ^PSB0._LEN, BLEN)
+	Store(CONFIG_MMCONF_BUS_NUMBER - 1, BMAX)
+	Store(CONFIG_MMCONF_BUS_NUMBER, BLEN)
+
 	Return(CRES) /* note to change the Name buffer */
 } /* end of Method(_SB.PCI0._CRS) */