System, Processes and Memory Management
0x00 (Graceful Program Exit)
The process'/task's ID is resolved by the kernel scheduler automatically. The process is killed, its page tables and any heap blocks it still owns are released, and a launcher waiting on it (fg) is woken.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
| unused | program return code | ✅ |
0x01 (System Information)
| Argument 1 | Argument 2 | Meaning | Implemented |
|---|---|---|---|
0x01 |
pointer to SysInfo struct |
Read the system information summary. | ✅ |
0x02 |
pointer to SysInfo struct |
Write the system information summary. (Currently, only ip_addr fields is written back from the struct; all other fields are ignored.) |
✅ |
system_path is NUL-terminated after the working directory. The call returns Busy (0xfa) instead of an untouched buffer when the system configuration lock cannot be taken.
0x02 (Real-Time Clock)
| Argument 1 | Argument 2 | Meaning | Implemented |
|---|---|---|---|
0x01 |
pointer to RTC struct |
Read the system time and date. | ✅ |
0x02 |
pointer to RTC struct |
Write the system time and date. | ❌ |
0x03 (Pipe handling)
| Argument 1 | Argument 2 | Meaning | Implemented |
|---|---|---|---|
0x01 |
pointer to circular buffer | Register a buffer to receive scancodes from IRQ1. | ✅ |
0x02 |
pointer to circular buffer | Unregister a buffer from receiving any scancodes from IRQ1. | ✅ |
0x03 |
pointer to circular buffer | Read from the registered buffer (IRQ1). | ✅ |
0x04 |
unused | Register current process to receive mouse packets (IRQ12). | ✅ |
0x05 |
pointer to output buffer | Drain up to 5 complete 3-byte packets (15 bytes) from the mouse ring buffer into the caller's buffer. Returns bytes written (always a multiple of 3). | ✅ |
0x06 |
unused | Unregister current process from receiving mouse packets (IRQ12). | ✅ |
0x04 (Tick count in milliseconds)
Get millisecond tick count since boot. Returns elapsed milliseconds in RAX. The resolution is one PIT tick, which is 1 ms at the current 1000 Hz rate (TICKS_PER_SECOND).
No argument is used. The syscall is implemented.
0x05 (Sleep)
Sleep for at least the given number of milliseconds. Rounded up to the next PIT tick (1 ms at 1000 Hz). Marks the calling process as Blocked; the scheduler wakes it automatically — no busy-wait.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
| duration in milliseconds | unused | ✅ |
0x0a (Allocate memory on heap)
Allocate a block from the userland heap (0xc00000-0xffffff). Returns the virtual address of the zeroed block in RAX as response, or 0x00 on failure.
When the 4 MiB are full, the heap grows once: an extension of an eighth of the RAM (at least 2 MiB, below 1 GiB) is added at 0xa000000, or past the tar archive when that lies there, mapped user-accessible in every process, and the allocation is served from it. A block can therefore come from either region; both are memory like any other to the caller. See Allocators for the details, and 0x3c for where the heap stands.
The heap is shared by all processes. Each block is tagged with the slot of the process that allocated it and is freed automatically when that process exits, is killed or crashes.
A heap block can be passed to any syscall that takes a pointer, as long as the buffer the call uses fits inside the block's region; see Pointer Arguments.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
| size in bytes | unused | ✅ |
0x0b (Reallocate memory on heap)
Reallocate a heap block. Tries in-place expansion first; falls back to allocate+copy+free. Returns the (possibly new) address, or 0x00 on failure. The block keeps its original owner.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
pointer to existing block (or 0x00) |
new size in bytes | ✅ |
0x0f (Free a heap block)
Free a heap block. Immediately coalesces adjacent free blocks.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
| pointer to block | 0x00 |
✅ |
0x3b (Kill process)
Kill a process by the PID reported by 0x2f (and printed by the shell's ts), not by scheduler slot. The target's page tables and heap blocks are released and its launcher, if parked on it, is woken.
Returns 0x00 on success, or FileNotFound (0xfe) when no live process has that PID.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
| PID | unused | ✅ |
0x3c (Memory information)
Fills a MemInfo with the usable RAM, the layout of the per-process frames, and the user heap (0x0a) added up block by block --- including how many bytes each process slot holds, and which task id sits in each slot, so the figures can be put next to 0x2f's list. The same numbers the kernel shell's heap and meminfo print.
Returns 0x00, InvalidInput (0xfc) for a pointer outside the user regions, or Busy (0xfa) when the heap or the scheduler is locked at that moment; ask again.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
pointer to MemInfo |
unused | ✅ |
0x3e (Power)
Restarts or switches off the machine. Neither comes back: acpi::shutdown tries the reset register or sleep state the ACPI tables name first, and then the chipset's reset control (0xcf9), the keyboard controller and a triple fault. Anything else in Argument 1 returns InvalidInput (0xfc); a kernel older than the call returns InvalidSyscall (0xff), which is how a caller tells that it is still running because the call is not there.
Memento uses it when its login dialog is left: that is the end of the session on the graphics kernel, where there is no shell to go back to.
| Argument 1 | Argument 2 | Implemented |
|---|---|---|
0x01 restart, 0x02 power off |
unused | ✅ |