[mp] Define an API for multiprocessor functions

Define an API for executing very limited functions on application
processors in a multiprocessor system, along with an x86-only
implementation.

The normal iPXE runtime environment is effectively non-existent on
application processors.  There is no ability to make firmware calls
(e.g. to write to a console), and there may be no stack space
available.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/src/include/ipxe/null_mp.h b/src/include/ipxe/null_mp.h
new file mode 100644
index 00000000..f89da5d9
--- /dev/null
+++ b/src/include/ipxe/null_mp.h
@@ -0,0 +1,36 @@
+#ifndef _IPXE_NULL_MP_H
+#define _IPXE_NULL_MP_H
+
+/** @file
+ *
+ * Null multiprocessor API implementation
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#ifdef MPAPI_NULL
+#define MPAPI_PREFIX_null
+#else
+#define MPAPI_PREFIX_null __null_
+#endif
+
+static inline __attribute__ (( always_inline )) mp_addr_t
+MPAPI_INLINE ( null, mp_address ) ( void *address ) {
+
+	return ( ( mp_addr_t ) address );
+}
+
+static inline __attribute__ (( always_inline )) void
+MPAPI_INLINE ( null, mp_exec_boot ) ( mp_func_t func __unused,
+				      void *opaque __unused ) {
+	/* Do nothing */
+}
+
+static inline __attribute__ (( always_inline )) void
+MPAPI_INLINE ( null, mp_start_all ) ( mp_func_t func __unused,
+				      void *opaque __unused ) {
+	/* Do nothing */
+}
+
+#endif /* _IPXE_NULL_MP_H */