From a7a8b39836ce74204380cc6770809ad73e8ac31f Mon Sep 17 00:00:00 2001
From: Jesse Brault <jbrault@mac.com>
Date: Fri, 27 Dec 2024 10:41:03 -0600
Subject: [PATCH] Write some documentation about op codes.

---
 doc/dvm.asciidoc | 218 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 218 insertions(+)

diff --git a/doc/dvm.asciidoc b/doc/dvm.asciidoc
index 2c331a6..b4a92a5 100644
--- a/doc/dvm.asciidoc
+++ b/doc/dvm.asciidoc
@@ -5,3 +5,221 @@ Jesse Brault <jbrault@mac.com>
 
 == Op Codes
 
+All numbers larger than `u8` are stored in **little-endian** format in raw bytecode.
+
+=== Move Byte
+
+Copies the operand into the target register.
+
+[source]
+----
+mov_byte(
+  target_register: u8,
+  operand: u8
+)
+----
+
+=== Move Int
+
+Copies the operand into the target register.
+
+[source]
+----
+mov_int(
+  target_register: u8,
+  operand: u32
+)
+----
+
+The operand is converted to an `i32` at runtime by the virtual machine.
+
+=== Move Long
+
+Copies the operand to the target register.
+
+[source]
+----
+mov_long(
+  target_register: u8,
+  operand: u64
+)
+----
+
+The operand is converted to an `i64` at runtime by the virtual machine.
+
+=== Move USize
+
+Copies the operand to the target register.
+
+[source]
+----
+mov_usize(
+  target_register: u8,
+  operand: usize
+)
+----
+
+Unlike most other operand types, this operand remains unsigned at runtime.
+
+=== Move Double
+
+Copies the operand to the target register.
+
+[source]
+----
+mov_double(
+  target_register: u8,
+  operand: u64
+)
+----
+
+The operand is converted to an `f64` at runtime by the virtual machine.
+
+=== Move Boolean
+
+Copies the operand to the target register.
+
+[source]
+----
+mov_boolean(
+  target_register: u8,
+  operand: u8
+)
+----
+
+The operand is converted to a `bool` at runtime by the virtual machine.
+
+=== Move Register
+
+Copies the value in one register to another.
+
+[source]
+----
+mov_register(
+  target_register: u8,
+  source_register: u8
+)
+----
+
+=== Load Byte
+
+Loads the target register with the `u8` stored at the offset from the base of the object stored in the source register.
+
+[source]
+----
+load_byte(
+  target_register: u8,
+  source_register: u8,
+  offset: usize
+)
+----
+
+The source register must contain a `DvmValue::Object` at runtime.
+
+=== Load Int
+
+Loads the target register with the `i32` stored at the offset from the base of the object stored in the source register.
+
+[source]
+----
+load_int(
+  target_register: u8,
+  source_register: u8,
+  offset: usize
+)
+----
+
+The source register must contain a `DvmValue::Object` at runtime.
+
+=== Load Long
+
+Loads the target register with the `i64` stored at the offset from the base of the object stored in the source register.
+
+[source]
+----
+load_long(
+  target_register: u8,
+  source_register: u8,
+  offset: usize
+)
+----
+
+The source register must contain a `DvmValue::Object` at runtime.
+
+=== Load Double
+
+=== Load USize
+
+=== Load Boolean
+
+=== Store
+
+Stores the value contained in the source register to the offset from the base of the object contained in the target register.
+
+[source]
+----
+store(
+  target_register: u8,
+  offset: usize,
+  source_register: u8
+)
+----
+
+The target register must contain a `DvmValue::Object` at runtime.
+
+=== Allocate
+
+Allocates memory for an object of the specified type and stores the allocated `DvmValue::Object` in the target register.
+
+[source]
+----
+alloc(
+  target_register: u8,
+  implementation_name_length: usize,
+  implementation_name: [u8]
+)
+----
+
+The `implementation_name` is the bytes array of a UTF-8-encoded string, and `implementation_name_length` is the length of that array.
+
+=== Deallocate
+
+Deallocates the memory for the object stored in the target register.
+
+[source]
+----
+dealloc(
+  target_register: u8
+)
+----
+
+The target register must contain a `DvmValue::Object` at runtime.
+
+=== Platform Call
+
+=== Invoke Function
+
+=== Invoke Virtual
+
+=== Invoke Dynamic
+
+=== Add
+
+[source]
+----
+add(
+  target_register: u8,
+  left_register: u8,
+  right_register: u8
+)
+----
+
+=== Subtract
+
+=== Multiply
+
+=== Divide
+
+=== Modulo
+
+=== Power