diff --git a/src/drivers/system76/dgpu/Kconfig b/src/drivers/system76/dgpu/Kconfig
index 5096671472..6baea52efd 100644
--- a/src/drivers/system76/dgpu/Kconfig
+++ b/src/drivers/system76/dgpu/Kconfig
@@ -3,3 +3,10 @@ config DRIVERS_SYSTEM76_DGPU
 	default n
 	help
 		System76 switchable graphics support
+
+#TODO: make this cleaner, use device tree?
+config DRIVERS_SYSTEM76_DGPU_DEVICE
+	hex
+	default 0x01
+	help
+		System76 switchable graphics root device number
diff --git a/src/drivers/system76/dgpu/acpi/dgpu.asl b/src/drivers/system76/dgpu/acpi/dgpu.asl
index a721934b71..225d4d0206 100644
--- a/src/drivers/system76/dgpu/acpi/dgpu.asl
+++ b/src/drivers/system76/dgpu/acpi/dgpu.asl
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 Device (\_SB.PCI0.PEGP) {
-	Name (_ADR, 0x00010000)
+	Name (_ADR, CONFIG_DRIVERS_SYSTEM76_DGPU_DEVICE << 16)
 
 	PowerResource (PWRR, 0, 0) {
 		Name (_STA, 1)
@@ -35,7 +35,8 @@ Device (\_SB.PCI0.PEGP.DEV0) {
 
 	// Memory mapped PCI express registers
 	// Not sure what this stuff is, but it is used to get into GC6
-	OperationRegion (RPCX, SystemMemory, 0xE0008000, 0x1000)
+        //TODO: use DGPU_DEVICE to generate address
+	OperationRegion (RPCX, SystemMemory, CONFIG_MMCONF_BASE_ADDRESS + 0x8000, 0x1000)
 	Field (RPCX, ByteAcc, NoLock, Preserve) {
 		PVID,   16,
 		PDID,   16,
diff --git a/src/drivers/system76/dgpu/ramstage.c b/src/drivers/system76/dgpu/ramstage.c
index eeb1607ed4..8bd102baf1 100644
--- a/src/drivers/system76/dgpu/ramstage.c
+++ b/src/drivers/system76/dgpu/ramstage.c
@@ -55,13 +55,13 @@ static struct device_operations dgpu_pci_ops_dev = {
 static void dgpu_above_4g(void *unused) {
 	struct device *pdev;
 
-	// Find PEG0
-	pdev = pcidev_on_root(1, 0);
+	// Find PEGP
+	pdev = pcidev_on_root(CONFIG_DRIVERS_SYSTEM76_DGPU_DEVICE, 0);
 	if (!pdev) {
-		printk(BIOS_ERR, "system76: failed to find PEG0\n");
+		printk(BIOS_ERR, "system76: failed to find PEGP\n");
 		return;
 	}
-	printk(BIOS_INFO, "system76: PEG0 at %p, %04x:%04x\n", pdev, pdev->vendor, pdev->device);
+	printk(BIOS_INFO, "system76: PEGP at %p, %04x:%04x\n", pdev, pdev->vendor, pdev->device);
 
     int fn;
     for (fn = 0; fn < 8; fn++) {