build: Use compile_time_request system for init, tasks, and shutdown

Avoid using linker magic to define the init, task, and shutdown
functions.  Instead, use the compile_time_request system.  This
simplifies the build and produces more efficient code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

scripts/buildcommands.py

@@ -13,6 +13,7 @@ import msgproto
 FILEHEADER = """
 /* DO NOT EDIT!  This is an autogenerated file.  See scripts/buildcommands.py. */
 
+#include "board/irq.h"
 #include "board/pgm.h"
 #include "command.h"
 #include "compiler.h"
@@ -119,6 +120,23 @@ ctr_lookup_static_string(const char *str)
 """
     return fmt % ("".join(code).strip(),)
 
+def build_call_lists(call_lists):
+    code = []
+    for funcname, funcs in call_lists.items():
+        func_code = ['    extern void %s(void);\n    %s();' % (f, f)
+                     for f in funcs]
+        if funcname == 'ctr_run_taskfuncs':
+            func_code = ['    irq_poll();\n' + fc for fc in func_code]
+        fmt = """
+void
+%s(void)
+{
+    %s
+}
+"""
+        code.append(fmt % (funcname, "\n".join(func_code).strip()))
+    return "".join(code)
+
 def build_param_types(all_param_types):
     sorted_param_types = sorted([(i, a) for a, i in all_param_types.items()])
     params = ['']
@@ -271,6 +289,7 @@ def main():
     encoders = []
     static_strings = []
     constants = {}
+    call_lists = {'ctr_run_initfuncs': []}
     # Parse request file
     f = open(incmdfile, 'rb')
     data = f.read()
@@ -314,6 +333,10 @@ def main():
             if name in constants and constants[name] != value:
                 error("Conflicting definition for constant '%s'" % name)
             constants[name] = value
+        elif cmd == '_DECL_CALLLIST':
+            funcname, callname = parts[1:]
+            cl = call_lists.setdefault(funcname, [])
+            cl.append(callname)
         else:
             error("Unknown build time command '%s'" % cmd)
     # Create unique ids for each message type
@@ -328,6 +351,7 @@ def main():
     all_param_types = {}
     parsercode = build_encoders(encoders, msg_to_id, all_param_types)
     static_strings_code = build_static_strings(static_strings)
+    call_lists_code = build_call_lists(call_lists)
     # Create command definitions
     cmd_by_id = dict((msg_to_id[messages_by_name.get(msgname, msgname)], cmd)
                      for msgname, cmd in commands.items())
@@ -342,8 +366,8 @@ def main():
                                      , static_strings, constants, version)
     # Write output
     f = open(outcfile, 'wb')
-    f.write(FILEHEADER + paramcode + parsercode + static_strings_code
-            + cmdcode + icode)
+    f.write(FILEHEADER + call_lists_code + static_strings_code
+            + paramcode + parsercode + cmdcode + icode)
     f.close()
 
     # Write data dictionary