Kernel/LibC: remove PATH resoltion from kernel

I have no idea why I had made PATH environment variable parsing
to be part of the kernel. Now the shell does the parsing and
environment syscall is no longer needed.

libc/include/sys/syscall.h

@@ -21,7 +21,6 @@ __BEGIN_DECLS
 #define SYS_SLEEP 17
 #define SYS_WAIT 18
 #define SYS_FSTAT 19
-#define SYS_SETENVP 20
 #define SYS_READ_DIR_ENTRIES 21
 #define SYS_SET_UID 22
 #define SYS_SET_GID 23

libc/stdlib.cpp

@@ -124,6 +124,16 @@ int putenv(char* string)
 		return -1;
 	}
 
+	if (!environ)
+	{
+		environ = (char**)malloc(sizeof(char*) * 2);
+		if (!environ)
+			return -1;
+		environ[0] = string;
+		environ[1] = nullptr;
+		return 0;
+	}
+
 	int cnt = 0;
 	for (int i = 0; string[i]; i++)
 		if (string[i] == '=')
@@ -151,10 +161,7 @@ int putenv(char* string)
 
 	char** new_envp = (char**)malloc(sizeof(char*) * (env_count + 2));
 	if (new_envp == nullptr)
-	{
-		errno = ENOMEM;
 		return -1;
-	}
 
 	for (int i = 0; i < env_count; i++)
 		new_envp[i] = environ[i];
@@ -164,8 +171,6 @@ int putenv(char* string)
 	free(environ);
 	environ = new_envp;
 
-	if (syscall(SYS_SETENVP, environ) == -1)
-		return -1;
 	return 0;
 }
 

libc/unistd.cpp

@@ -14,8 +14,23 @@ char** environ;
 extern void init_malloc();
 extern "C" void _init_libc(char** _environ)
 {
-	environ = _environ;
 	init_malloc();
+
+	if (!_environ)
+		return;
+
+	size_t env_count = 0;
+	while (_environ[env_count])
+		env_count++;
+	
+	environ = (char**)malloc(sizeof(char*) * env_count + 1);
+	for (size_t i = 0; i < env_count; i++)
+	{
+		size_t bytes = strlen(_environ[i]) + 1;
+		environ[i] = (char*)malloc(bytes);
+		memcpy(environ[i], _environ[i], bytes);
+	}
+	environ[env_count] = nullptr;
 }
 
 void _exit(int status)