Module usertest 

Minimal Ring 3 test task for Strat9-OS.

Creates a user address space with a tiny machine code blob that:

1. Calls SYS_DEBUG_LOG to print “Hello Ring 3!” to serial
2. Calls SYS_PROC_EXIT to cleanly exit

This tests the full SYSCALL/SYSRET pipeline without needing an ELF loader.

Constants

USER_CODE_ADDR 🔒

User code virtual address (must be in lower half, page-aligned).

USER_STACK_ADDR 🔒

User stack virtual address (page-aligned).

USER_STACK_TOP 🔒

User stack top (stack grows down, so this is base + 4096).

Statics

USER_TASK_AS 🔒

Static storage for the user address space (accessed by the trampoline).

Functions

create_user_test_task

Create and schedule a minimal Ring 3 test task.

ring3_trampoline 🔒

Trampoline that switches to user address space and does IRETQ to Ring 3.

write_user_code 🔒

Write the user-mode test program into the code page.