Add libcaliptra APIs to check if ready for certain boot milestones.

Previously the only APIs blocked until it reached those milestones. Now they can be checked asynchronously. This is also how `caliptra_is_csr_ready` works.

libcaliptra/inc/caliptra_api.h

@@ -40,16 +40,34 @@ bool caliptra_ready_for_fuses(void);
 //          STILL_READY_FOR_FUSES   - Flow status still indicates ready for fuses after writing fuse done
 int caliptra_init_fuses(const struct caliptra_fuses *fuses);
 
+/**
+ * caliptra_is_ready_for_firmware
+ *
+ * Checks if Caliptra hardware is ready for firmware upload
+ *
+ * @return bool True if ready, false otherwise
+ */
+uint32_t caliptra_is_ready_for_firmware(void);
+
 /**
  * caliptra_ready_for_firmware
  *
  * Waits until Caliptra hardware is ready for firmware upload or until
  * Caliptra reports an error
  *
- * @return bool True if ready, false otherwise
+ * @return int 0 if ready, Caliptra error otherwise
  */
 uint32_t caliptra_ready_for_firmware(void);
 
+/**
+ * caliptra_is_ready_for_runtime
+ *
+ * Checks if Caliptra hardware is ready for runtime commands
+ *
+ * @return bool True if ready, false otherwise
+ */
+uint32_t caliptra_is_ready_for_runtime(void);
+
 /**
  * caliptra_ready_for_runtime
  *

libcaliptra/src/caliptra_api.c

@@ -324,30 +324,41 @@ uint32_t caliptra_read_fw_fatal_error()
     return caliptra_read_fw_error_fatal();
 }
 
+/**
+ * caliptra_is_ready_for_firmware
+ *
+ * Checks if Caliptra hardware is ready for firmware upload
+ *
+ * @return bool True if ready, false otherwise
+ */
+uint32_t caliptra_is_ready_for_firmware(void)
+{
+    uint32_t status = caliptra_read_status();
+    return (status & GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_FW_MASK) == GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_FW_MASK;
+}
+
 /**
  * caliptra_ready_for_firmware
  *
  * Waits until Caliptra hardware is ready for firmware upload or until
  * Caliptra reports an error
  *
- * @return bool True if ready, false otherwise
+ * @return int 0 if ready, Caliptra error otherwise
  */
 uint32_t caliptra_ready_for_firmware(void)
 {
-    uint32_t status;
     uint32_t fatal_error;
     bool ready = false;
 
     do
     {
-        status = caliptra_read_status();
         fatal_error = caliptra_read_fw_fatal_error();
 
         if (fatal_error != 0)
         {
             return fatal_error;
         }
-        else if ((status & GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_FW_MASK) == GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_FW_MASK)
+        else if (caliptra_is_ready_for_firmware())
         {
             ready = true;
         }
@@ -360,6 +371,19 @@ uint32_t caliptra_ready_for_firmware(void)
     return 0;
 }
 
+/**
+ * caliptra_is_ready_for_runtime
+ *
+ * Checks if Caliptra hardware is ready for runtime commands
+ *
+ * @return bool True if ready, false otherwise
+ */
+uint32_t caliptra_is_ready_for_runtime(void)
+{
+    uint32_t status = caliptra_read_status();
+    return (status & GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_RUNTIME_MASK) == GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_RUNTIME_MASK;
+}
+
 /**
  * caliptra_ready_for_runtime
  *
@@ -370,20 +394,18 @@ uint32_t caliptra_ready_for_firmware(void)
  */
 uint32_t caliptra_ready_for_runtime(void)
 {
-    uint32_t status;
     uint32_t fatal_error;
     bool ready = false;
 
     do
     {
-        status = caliptra_read_status();
         fatal_error = caliptra_read_fw_fatal_error();
 
         if (fatal_error != 0)
         {
             return fatal_error;
         }
-        else if ((status & GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_RUNTIME_MASK) == GENERIC_AND_FUSE_REG_CPTRA_FLOW_STATUS_READY_FOR_RUNTIME_MASK)
+        else if (caliptra_is_ready_for_runtime())
         {
             ready = true;
         }