From 7d735c335492a84ca4219a886754ba1cde2f415a Mon Sep 17 00:00:00 2001
From: Stefan Bucur <stefanb@zytor.com>
Date: Mon, 28 Jul 2008 21:33:14 -0700
Subject: Implemented the initialization system of an ELF module.

---
 com32/elflink/elf_module.c | 30 +++++++++++++++++++++++++-
 com32/elflink/elf_module.h |  7 +++++--
 com32/elflink/test_com32.c | 52 ++++++++++++++++++++++++++++++++++++++--------
 3 files changed, 77 insertions(+), 12 deletions(-)

diff --git a/com32/elflink/elf_module.c b/com32/elflink/elf_module.c
index fbd596e4..fedebf7f 100644
--- a/com32/elflink/elf_module.c
+++ b/com32/elflink/elf_module.c
@@ -778,6 +778,28 @@ static int check_symbols(struct elf_module *module) {
 	return 0;
 }
 
+static int extract_operations(struct elf_module *module) {
+	Elf32_Sym *init_sym = module_find_symbol(MODULE_ELF_INIT_PTR, module);
+	Elf32_Sym *exit_sym = module_find_symbol(MODULE_ELF_EXIT_PTR, module);
+
+	if (init_sym == NULL) {
+		DBG_PRINT("Cannot find initialization routine.\n");
+		return -1;
+	}
+	if (exit_sym == NULL) {
+		DBG_PRINT("Cannot find exit routine.\n");
+		return -1;
+	}
+
+	module->init_func = (module_init_func*)module_get_absolute(
+								init_sym->st_value, module);
+
+	module->exit_func = (module_exit_func*)module_get_absolute(
+								exit_sym->st_value, module);
+
+	return 0;
+}
+
 // Loads the module into the system
 int module_load(struct elf_module *module) {
 	int res;
@@ -806,16 +828,22 @@ int module_load(struct elf_module *module) {
 	// Check the symbols for duplicates / missing definitions
 	CHECKED(res, check_symbols(module), error);
 
+	// Obtain constructors and destructors
+	CHECKED(res, extract_operations(module), error);
+
 	// Add the module at the beginning of the module list
 	list_add(&module->list, &modules);
 
 	// Perform the relocations
 	resolve_symbols(module);
 
+
+
 	// The file image is no longer needed
 	image_unload(module);
 
-	DBG_PRINT("MODULE %s LOADED SUCCESSFULLY\n", module->name);
+	DBG_PRINT("MODULE %s LOADED SUCCESSFULLY (&init@0x%08X, &exit@0x%08X)\n",
+			module->name, module->init_func, module->exit_func);
 
 	return 0;
 
diff --git a/com32/elflink/elf_module.h b/com32/elflink/elf_module.h
index cdc2254f..5e6a3719 100644
--- a/com32/elflink/elf_module.h
+++ b/com32/elflink/elf_module.h
@@ -15,6 +15,9 @@
 #define MODULE_ELF_TYPE			ET_DYN
 #define MODULE_ELF_MACHINE		EM_386
 
+#define MODULE_ELF_INIT_PTR		"__module_init_ptr"
+#define MODULE_ELF_EXIT_PTR		"__module_exit_ptr"
+
 
 typedef int (*module_init_func)(void);
 typedef void (*module_exit_func)(void);
@@ -29,8 +32,8 @@ struct elf_module {
 	struct list_head	dependants;		// Head of module dependants list
 	struct list_head	list;		// The list entry in the module list
 
-	module_init_func	init_func;	// The initialization entry point
-	module_exit_func	exit_func;	// The module finalization code
+	module_init_func	*init_func;	// The initialization entry point
+	module_exit_func	*exit_func;	// The module finalization code
 
 
 	void				*module_addr; // The module location in the memory
diff --git a/com32/elflink/test_com32.c b/com32/elflink/test_com32.c
index 90643937..b9f20bd2 100644
--- a/com32/elflink/test_com32.c
+++ b/com32/elflink/test_com32.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <console.h>
+#include <string.h>
 
 #include "elf_module.h"
 
@@ -10,7 +11,6 @@
 #define ELF_DIRECTORY		"/dyn/"
 
 static struct elf_module    *mod_root;
-static struct elf_module	*mod_klibc;
 
 int modules_com32_setup() {
 	int res;
@@ -39,26 +39,60 @@ int modules_com32_setup() {
 	return 0;
 }
 
+int modules_com32_load(char *name) {
+	char full_name[MODULE_NAME_SIZE];
+	int res;
+
+	strcpy(full_name, ELF_DIRECTORY);
+	strcat(full_name, name);
+
+	struct elf_module *module = module_alloc(full_name);
+
+	res = module_load(module);
+
+	if (res != 0)
+		return res;
+
+	if (*(module->init_func) != NULL) {
+		res = (*(module->init_func))();
+		printf("Initialization function returned: %d\n", res);
+	} else {
+		printf("No initialization function present.\n");
+	}
+
+	return res;
+}
+
+void print_usage() {
+	printf("Usage: test_com32 module ...\n");
+	printf("Where:\n");
+	printf("\tmodule\tThe name of an ELF module to load, eg. hello.dyn\n");
+	printf("\n");
+}
+
 void modules_com32_finalize() {
 	modules_term();
 }
 
 int main(int argc, char **argv) {
-	int res;
+	int res, i;
 
 	// Open a standard r/w console
 	openconsole(&dev_stdcon_r, &dev_stdcon_w);
 
+	argc--;
+	argv++;
+
+	if (argc == 0) {
+		print_usage();
+		return 1;
+	}
+
 	// Initializing the module subsystem
 	res = modules_com32_setup();
 
-	// Load klibc
-	mod_klibc = module_alloc(ELF_DIRECTORY KLIBC_NAME);
-	module_load(mod_klibc);
-
-	if (res != 0) {
-		printf("ERROR: Could not fully initialize the module!\n");
-		return res;
+	for (i = 0; i < argc; i++) {
+		modules_com32_load(argv[i]);
 	}
 
 	modules_com32_finalize();
-- 
cgit