init: Dynamically set CONFIG_TPM at boot

Dynamically set CONFIG_TPM at boot based on the presence of /dev/tpm0.
This allows the same board/device with and without a TPM to be handled
by a single board definition and single firmware image. It also eliminates
the need to explictly define CONFIG_TPM in board config files.

Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>

initrd/init

@@ -44,6 +44,13 @@ hwclock -l -s
 . /etc/functions
 . /etc/config
 
+# set CONFIG_TPM dynamically before init
+if [ -e /dev/tpm0 ]; then
+ export CONFIG_TPM='y'
+else
+ export CONFIG_TPM='n'
+fi
+
 if [ "$CONFIG_COREBOOT" = "y" ]; then
  /bin/cbfs-init
 fi
@@ -89,6 +96,13 @@ if [ "$boot_option" = "r" ]; then
  exit
 fi
 
+# Override CONFIG_TPM and persist via user config
+if [ -e /dev/tpm0 ]; then
+ echo "CONFIG_TPM=y" >> /etc/config.user
+else
+ echo "CONFIG_TPM=n" >> /etc/config.user
+fi
+
 combine_configs
 . /tmp/config