efi-loader: add efi_has_tpm2() helper

The helper checks if the UEFI firmware is hooked up to a TPM2 chip. This
is useful to know in trusted boot scenarios, in particular during early
boot in auto-enroll scenarios where we want to know whether TPM2 is
available or not, and the Linux drivers are not loaded yet, and where it
might or not be worth waiting for it.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/shared/efi-loader.h b/src/shared/efi-loader.h
index 7621794736..bc5769bb6b 100644
--- a/src/shared/efi-loader.h
+++ b/src/shared/efi-loader.h
@@ -29,6 +29,8 @@ int efi_loader_get_features(uint64_t *ret);
 int efi_loader_get_config_timeout_one_shot(usec_t *ret);
 int efi_loader_update_entry_one_shot_cache(char **cache, struct stat *cache_stat);
 
+bool efi_has_tpm2(void);
+
 #else
 
 static inline int efi_reboot_to_firmware_supported(void) {
@@ -91,6 +93,10 @@ static inline int efi_loader_update_entry_one_shot_cache(char **cache, struct st
         return -EOPNOTSUPP;
 }
 
+static inline bool efi_has_tpm2(void) {
+        return false;
+}
+
 #endif
 
 bool efi_loader_entry_name_valid(const char *s);