diff --git a/kernel_module/pci.c b/kernel_module/pci.c
index c01f1fa..7873fd7 100644
--- a/kernel_module/pci.c
+++ b/kernel_module/pci.c
@@ -1,4 +1,6 @@
 /*
+Only teted for x86.
+
 Usage:
 
 	/pci.sh
diff --git a/kernel_module/platform_device.c b/kernel_module/platform_device.c
index a5e04d5..a0f6192 100644
--- a/kernel_module/platform_device.c
+++ b/kernel_module/platform_device.c
@@ -1,6 +1,10 @@
 /*
 Only works for ARM.
 
+Uses the hw/misc/lkmc_platform_device.c minimal device added in our QEMU fork.
+
+See: https://stackoverflow.com/questions/28315265/how-to-add-a-new-device-in-qemu-source-code/44612957#44612957
+
 Expected outcome after insmod:
 
 - QEMU reports MMIO with printfs
diff --git a/linux b/linux
index 54e66cc..361bb62 160000
--- a/linux
+++ b/linux
@@ -1 +1 @@
-Subproject commit 54e66cc228125e6c223214bac7ada398401e7b90
+Subproject commit 361bb623671a52a36a077a6dd45843389a687a33