Changeset 697

Timestamp:

Sep 11, 2003, 9:08:36 PM (22 years ago)

Author:

bird

Message:

Startup docs.

File:

• trunk/src/emx/src/lib/startup/startup.c (modified) (1 diff, 1 prop)

trunk/src/emx/src/lib/startup/startup.c

@@ -97 +97 @@
     }
 }
+
+
+
+/** @page Startup
+ *
+ * Quick description of how we startup a process which modules uses LIBC.
+ *
+ * The load first loads the DLLs of the process, calling their _DLL_InitTerm
+ * entrypoints in order of dependencies. If you're using dynamic LIBC this
+ * will be initiated first of the LIBC-based modules.
+ *
+ * LIBCxy.DLL:
+ *      - dll0.s gets control and calls __init_dll in sys/__initdll.c
+ *          - __init_dll calls __init_os_version() to set _osminor,_osmajor globals.
+ *          - __init_dll creates _sys_heap_fmutex.
+ *          - __init_dll initiates _sys_pid and _sys_ppid globals.
+ *          - __init_dll allocates and initiatlized the _sys_private_heap heap, which is
+ *            operated by DosSubSetMem() and it's friends.
+ *          - __init_dll then initializes _sys_thread_table and calls __newthread() in
+ *            sys/__newthread.c to create the thread 1 entry.
+ *          - __init_dll then intializes _sys_clock0_ms with the current MS count.
+ *      - dll0.s calls _DLL_InitTerm in startup/dllinit.c.
+ *          - _DLL_InitTerm calls _CRT_init() in startup/startup.c to initialize the CRT.
+ *              - _CRT_init calls init_files() to initialize the file handle tables.
+ *              - _CRT_init then call all the crt init functions in __crtinit1__.
+ *          - _DLL_InitTerm calls __ctordtorInit() to initate any exception structures and
+ *            construct static C++ objects.
+ *      - dll0.s then returns to DOSCALL1.DLL and back to the kernel.
+ *
+ * Your.DLL:
+ *      - dll0.s gets control and calls __init_dll() in sys/__initdll.c
+ *          - __init_dll returns at once since already done during LIBCxy.DLL init.
+ *      - dll0.s calls _DLL_InitTerm in startup/dllinit.c.
+ *          - _DLL_InitTerm calls _CRT_init() in startup/startup.c to initialize the CRT.
+ *              - _CRT_init return at once since already done during LIBCxy.DLL init.
+ *          - _DLL_InitTerm calls __ctordtorInit() to initate any exception structures and
+ *            construct static C++ objects in _this_ DLL.
+ *      - dll0.s then returns to DOSCALL1.DLL and back to the kernel.
+ *
+ * Your.exe:
+ *      - crt0.s gets control and calls ___init_app in sys/386/appinit.s which forwards
+ *        the call to __init() in sys/__init.c.
+ *          - __init() calls __init_dll() which returns at once because of LIBCxy.DLL init.
+ *          - __init() parse the environment and commandline to figure out how much stack
+ *            to use for their arrays and the argument copy.
+ *          - __init() the allocates the stack space space, adding an exception handler struct.
+ *          - __init() parse the environment and create the array using allocated stack space.
+ *          - __init() parse the commandline creating both array and a copy using allocated
+ *            stack space.
+ *          - __init() installs the exception handler.
+ *          - __init() set the signal focus.
+ *          - __init() then 'returns' thru the hack called ___init_ret in sys/386/appinit.s
+ *      - crt0.s now get control back with esp pointing to the array of env vars.
+ *      - crt0.s sets environ and _org_environ.
+ *      - crt0.s sets up the call frame for main() by skipping it's way thru the env and
+ *        arg arrays.
+ *      - crt0.s calls _CRT_init() in startup/startup.c to initialize the CRT which returns
+ *        immediately since since already done during LIBCxy.DLL init.
+ *      - crt0.s the calls main() with the three arguments setup earlier.
+ *      - crt0.s then calls exit() with the return value of main().
+ *          - exit() will call all the registered at_exit functions.
+ *          - exit() will call DosExit with the exit code and terminate the process.
+ */