fe16-vm is simple 16bit virtual machine based on RISC architecture.
| Opcode | Description |
|---|---|
| mov | Move |
| add | Add |
| sub | Sub |
| and | Logical AND |
| xor | Logical XOR |
| push | Push to stack |
| pop | Pop from stack |
| jmp | Jump to line |
| cmp | Compares two operands |
| jme | Jump to line if equal |
| sys | System call |
| call | Call procedure |
| ret | Return from procedure |
| Register | Description |
|---|---|
| f0 | |
| f1 | |
| f2 | |
| f3 | |
| f4 | |
| fsp | Stack pointer |
| fcd | Last operation status |
| fpc | Program counter |
fe16-vm has only 8 registers. Of these, only 5 are for general purpose ( f0 ... f4 ). Other 3 registers for program counter, storing flags and stack pointer.
| Syscall Name | f0 | f1 | f2 | f3 | f4 |
|---|---|---|---|---|---|
| exit | exit code | - | - | - | 0x1 |
| write | file descriptor | string length | - | - | 0x2 |
| read | file descriptor | string length | - | - | 0x3 |