View source for GPU/Commands

This page describes the structure of the buffer for [[GSP_Shared_Memory|GX command]] 1 with the registers at [[GPU|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.

Invalid GPU command parameters can cause the GPU to hang, this then causes the GSP module to hang as well.

=== Command Header ===
{| class="wikitable" border="1"
!  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 ===
{| class="wikitable" border="1"
!  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 also used elsewhere for beginning rendering of object(s) as well.
|-
| 0x000F0111
| Value 0x1
| This command is immediately before CmdID 0x000F0110, however CmdID 0x000F0110 doesn't always follow this command.
|-
| 0x000F0040
| u32, valid values are 0x1 and 0x2, values 0x0 and 0x3 have the same effect as value 0x2. Only bits 1-0 are used.
| Value 2 = GL_FRONT/GL_CW or GL_BACK/GL_CCW. Value 1 = GL_FRONT/GL_CCW or GL_BACK/GL_CW.
|-
| 0x000F0041
| float
| See command set 0x000F0041.
|-
| 0x000F0042
| float
| See command set 0x000F0041.
|-
| 0x000F0043
| float
| See command set 0x000F0041.
|-
| 0x000F0044
| float
| See command set 0x000F0041.
|-
| 0x801F004D
| First word in parameter structure
| ?
|-
| 0x0002025E
| u32, val<<8.
| This sets the GL rendering mode.
|-
| 0x000F0068
| u32
| See command set 0x000F0041.
|-
| 0x000F006E
| u32
| This is used immediately after CmdID 0x000F011E, with the same input parameter value as CmdID 0x000F011E.
|-
| 0x809F0081
| 
| This is used to set the current texture info used for rendering, see command set [[GPU_Textures|0x809F0081]].
|-
| 0x000F008E
| u32 color type
| This command sets the texture color type, see command set [[GPU_Textures|0x809F0081]].
|-
| 0x00020100
| u32, value is 0x00E40100
| This command is used immediately before CmdID 0x000F0101.
|-
| 0x000F0101
| u32
| Color related?
|-
| 0x000F0104
| u32
| glAlphaFunc()?
|-
| 0x00010107
| 
| See command set CmdID 0x00010107.
|-
| 0x00020107
| 
| See command set CmdID 0x00010107.
|-
| 0x00030107
| 
| See command set CmdID 0x00030107.
|-
| 0x000F0116
| u32
| Unknown, this is used immediately after CmdID 0x000F011D.
|-
| 0x000F0117
| u32
| Unknown, normally the input parameter is value 0x2.
|-
| 0x000F011C
| Physical address>>3
| Normally this address is located in VRAM. This command is used immediately after 0x000F0116.
|-
| 0x000F011D
| Physical address>>3
| This initializes the framebuffer address used for rendering, this framebuffer is used for the input framebuffer with [[GSP_Shared_Memory|GX command]] 3 and 4. This command is used immediately after CmdID 0x000F0117.
|-
| 0x000F011E
| u32
| This sets the width and height for the framebuffer used for rendering. Therefore this is glViewport() with x=0 and y=0. This is used immediately after CmdID 0x000F011C.
|-
| 0x826F0200
| 
| See command set [[GPU_GL_Arrays|0x826F0200]].
|-
| 0x00080126
| 
| See command set CmdID 0x00030107.
|-
| 0x000F0227
| u32
| This specifies the address of an array containing vertex array indices, and the data-type of the indices, used for rendering primitives. See command set [[GPU_GL_Arrays|glDrawElements()]].
|-
| 0x000F0228
| u32 total elements in the array to use for rendering.
| See command set [[GPU_GL_Arrays|glDrawElements()]].
|-
| 0x803F0232
| 
| See command set [[GPU_GL_Arrays|0x826F0200]].
|-
| 0x000F02B0
| u32, value is <nowiki>0x7FFF0000 | val</nowiki>.
| Texture related?
|-
| 0x801F02BB
| 
| See command set [[GPU_GL_Arrays|0x826F0200]].
|-
| 0x000F02C0
| <nowiki>0x80000000 | Type</nowiki>
| This is used immediately before CmdID 0xXXXF02C1. This type field controls the command parameter buffer type.
|-
| 0xXXXF02C1
| First word in the first entry
| A list of entries follow this command.
|}

==== Command Sets ====

===== glDrawElements() =====
See [[GPU_GL_Arrays|GPU GL Arrays]].

===== CmdID 0x809F0081 =====
This sets current texture info, see [[GPU Textures|GPU textures]].

===== CmdID 0x000F0041 =====
{| class="wikitable" border="1"
!  Command Index
!  CommandID
!  Parameter
!  Description
|-
| 0
| 0x000F0041
| float
| This corresponds to the framebuffer width.
|-
| 1
| 0x000F0043
| float
| This corresponds to the framebuffer height.
|-
| 2
| 0x000F0042
| float
| This corresponds to the framebuffer width.
|-
| 3
| 0x000F0044
| float
| This corresponds to the framebuffer height.
|-
| 4
| 0x000F0068
| u32
| This sets the X/Y coordinates used for glViewport().
|}

This command set initializes the projection matrix.

===== CmdID 0x00030107 =====
{| class="wikitable" border="1"
!  Command Index
!  CommandID
!  Parameter
!  Description
|-
| 0
| 0x00030107
| 
| 
|-
| 1
| 0x00080126
| type<<24
| 
|}

This command set is used for disabling the alpha-testing info set by command set 0x00010107? The GL AlphaFunction used here is normally GL_ALWAYS.

===== CmdID 0x00010107 =====
{| class="wikitable" border="1"
!  Command Index
!  CommandID
!  Parameter
!  Description
|-
| 0
| 0x00010107
| Same format as CmdID 0x00030107.
| 
|-
| 1
| 0x00080126
| type<<24
| 
|-
| 0
| 0x00020107
| Same value as CmdID 0x00030107.
| 
|}

=== Parameter format for CmdIDs 0x00030107, 0x00020107, and 0x00010107 ===
{| class="wikitable" border="1"
!  Bit
!  Description
|-
| 0
| 0 = disable GL_ALPHA_TEST, 1 = enable GL_ALPHA_TEST?
|-
| 3-1
| Unused?
|-
| 7-4
| Alpha function
|-
| 11-8
| Color to blend with?
|-
| 12
| ?
|-
| 31-13
| Unused
|}

==== Alpha function values ====
{| class="wikitable" border="1"
!  Value
!  GL AlphaFunction
|-
| 0
| GL_NEVER
|-
| 1
| GL_ALWAYS
|-
| 2
| GL_EQUAL
|-
| 3
| GL_NOTEQUAL
|-
| 4
| GL_LESS
|-
| 5
| GL_LEQUAL
|-
| 6
| GL_GREATER
|-
| 7
| GL_GEQUAL
|}

=== Alpha types for CmdID 0x00080126 ===
{| class="wikitable" border="1"
!  Type
!  GL AlphaFunction
|-
| 0
| GL_NEVER
|-
| 1
| GL_ALWAYS
|-
| 2
| GL_GREATER/GL_GEQUAL
|-
| 3
| The remaining GL alpha functions.
|}

=== Parameter value format for CmdID 0x000F0104 ===
{| class="wikitable" border="1"
!  Bit
!  Description
|-
| 0
| 0 = disable GL_ALPHA_TEST, 1 = enable GL_ALPHA_TEST?
|-
| 3-1
| Unused?
|-
| 7-4
| Alpha function
|-
| 15-8
| u8 ref, range is 0-255?
|-
| 31-16
| Unused?
|}

This is glAlphaFunc()?

=== Parameter value format for CmdID 0x000F011E ===
{| class="wikitable" border="1"
!  Bit
!  Description
|-
| 11-0
| Framebuffer/viewport width
|-
| 23-12
| Framebuffer/viewport height - 1
|-
| 24
| Must be set
|-
| 31-25
| Unused?
|}

This specifies the width/height for glViewport(). Normally the framebuffer width and height is set to the same [[GPU|dimensions]] used with GX [[GSP_Shared_Memory|command]] 3 and 4.

=== Parameter value format for CmdID 0x000F0068 ===
{| class="wikitable" border="1"
!  Bit
!  Description
|-
| 15-0
| X
|-
| 31-16
| Y
|}

This specifies the X/Y coordinates for glViewport().

=== Entries for CmdID 0xXXXF02C1 ===
{| class="wikitable" border="1"
!  Index Word
!  Description
|-
| 0
| float
|-
| 1
| float
|-
| 2
| float
|}

==== Color Entry ====
{| class="wikitable" border="1"
!  Index Word
!  Description
|-
| 0
| float Red component
|-
| 1
| float Blue component
|-
| 2
| float Green component
|-
| 3
| float Alpha?
|-
| 4
| float
|-
| 5
| float
|}

==== Vertex Entry ====
{| class="wikitable" border="1"
!  Index Word
!  Description
|-
| 0
| float X coordinate
|-
| 1
| float Y coordinate
|-
| 2
| float Z coordinate
|}

Type 0x14 is used for specifying vertices, however the vertex array can be used for specifying vertices as well.

=== Types for CmdID 0x000F02C0 ===
{| class="wikitable" border="1"
!  Value
!  Entries per chunk
!  Description
|-
| 0x00
| 4
| Related to model-view matrix translation?
|-
| 0x04
| 4
| Unknown, this is used immediately after type 0x00.
|-
| 0x08
| One color entry via two CmdID 0xXXXF02C1 entries.
| Sets the color.
|-
| 0x0A
| 4
| Texture coordinates
|-
| 0x0B
| 3
| ?
|-
| 0x0C, 0x0D
| 3
| Related to type 0x0A?
|-
| 0x0E
| 4
| Related to type 0x0A?
|-
| 0x14
| <=30
| Geometry vertices
|-
| 0x4C
| 4
| ?
|-
| 0x50, 0x53, and 0x56
| 1
| ?
|-
| 0x51, 0x54, and 0x57
| 1
| ?
|-
| 0x52, 0x55, and 0x58
| 1
| ?
|-
| 0x59
| 1
| Unknown, the entry data is floats converted from s32s.
|-
| 0x5A
| 2
| Color related?
|-
| 0x5C
| 1
| ?
|}