Session Manager (smss.exe)

Overview

The Session Manager (smss.exe) is the first user-mode process started by the kernel. It is responsible for initializing the user session and starting critical system processes.

Responsibilities

• Create initial user session
• Start CSRSS (Client/Server Runtime Subsystem)
• Initialize session environment
• Start Winlogon (or FreeWorld equivalent)
• Manage session lifecycle
• Register with kernel service manager
• Monitor critical system processes

Service Registration

SMSS registers itself with the kernel service manager on startup:

#include "libc/syscalls/service_syscalls.h"

int main(int argc, char** argv) {
    // Initialize kernel service manager
    if (service_manager_init() != 0) {
        fprintf(stderr, "smss: Failed to initialize kernel service manager\n");
        return 1;
    }

    // Register smss service
    if (service_register("smss", "/sbin/smss", 
                        SERVICE_TYPE_SIMPLE, SERVICE_RESTART_ALWAYS) != 0) {
        fprintf(stderr, "smss: Failed to register service\n");
        return 1;
    }

    // ... rest of initialization
}

Boot Sequence

1. Kernel starts smss.exe
2. smss.exe creates session 0
3. smss.exe starts csrss.exe
4. smss.exe starts freeworldlogon.exe
5. smss.exe waits for session termination

Implementation

smss.exe is implemented as a Node.js process that runs at system startup, managing the session initialization sequence.