GPU/Commands

This page describes the structure of the buffer for GX command 1 with the registers at 0x1EF018E0. This buffer is used for GPU commands including OpenGL commands, each 8-byte entry in the buffer is a command. Cmd+0 is the command parameter, and cmd+4 is the command header.

Command Header

Bit	Description
19-0	Command ID
30-20	Total words following the command, if any.
31	?

The first word in the parameter data structure is the command parameter value, the rest of the data structure is from the data following the command. The word after the last data structure word is padding when needed for 8-byte alignment, for the following command.

Commands

CommandID	Parameter	Description
0x000F0010	Value is 0x12345678	This command is always the last command in the buffer.
0x000F0110	Value 0x1	This command is immediately before CmdID 0x000F0010, this is used elsewhere in the buffer as well.
0x000F0111	Value 0x1	This command is immediately before CmdID 0x000F0110, however CmdID 0x000F0110 doesn't always follow this command.
0x000F0041	float Z vector	This sets Z scaling for the current matrix.
0x000F0042	float Y vector	This sets Y scaling for the current matrix.
0x000F0043	float unknown	?
0x000F0044	float X vector	This sets X scaling for the current matrix.
0x801F004D	First word in parameter structure	?
0x000F02C0	0x80000000 | Type	This is used immediately before CmdID 0xXXXF02C1. This type field controls the command parameter buffer type, 0x00 is for regular vertices.
0xXXXF02C1	float X coordinate for the first vertex	The vertex entries is the data following the command.

Vertex Entry

Index Word	Description
0	float X coordinate
1	float Y coordinate
2	float Z coordinate