ABI
Syscall Table
Overview of the SlopOS syscall ABI
The syscall table is part of the SlopOS ABI. The source tree defines the exact numeric assignments, table size, and constants. These docs describe the shape of the interface and the rules for keeping it stable.
Groups
| Group | Examples |
|---|---|
| Core | yield, exit, time, system information, reboot |
| Random and roulette | entropy and Wheel of Fate calls |
| Filesystem | path operations, fd operations, metadata, directory listing |
| Memory | heap break, mappings, protection, memfd, truncate |
| Process | spawn, wait, terminate, exec, fork, clone, identity |
| SMP | CPU count, current CPU, affinity |
| Signals | actions, masks, delivery, return, signalfd |
| Poll and descriptors | poll, select, pipe, dup, fcntl, ioctl, pidfd |
| Networking | sockets, bind/listen/accept/connect, TCP/UDP I/O, DNS, options |
| UI and TTY | framebuffer, input, clipboard, font, pty, terminal I/O |
| SlopRing | setup, enter, fixed/provided buffer registration |
| Testing | kernel/userland test reporting and test-phase control |
Stability rules
- Numeric assignments are canonical in the ABI source, not in prose.
- Assigned numbers stay stable. Removed or reserved syscalls leave gaps.
- New syscalls use the next available assignment from the source ABI module.
- Structs shared across the boundary use fixed representation and explicit layout tests.
- Userland wrappers should import ABI constants instead of duplicating numbers.
- Public docs should describe behavior and link to generated or source ABI when exact values are required.
Return convention
Handlers return non-negative values on success and negative errno values on
failure. Unknown table slots return -ENOSYS.
See Adding a syscall before extending the ABI.