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.

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

Command Header

Bit	Description
15-0	Command ID
19-16	Parameter mask
30-20	Total words following the command, if any.
31	Command grouping bit

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.

Parameter masking

Bits 16-19 in the command header are not part of the command ID but in fact a parameter mask : bit 16 indicates that the LSB of the parameter will be written, bit17 that the parameter's second LSB will be written etc. This means that for instance commands 0x00020107 and 0x00010107 refer to the same thing but write different parts of the parameter.

Command grouping

In certain circumstances it is possible to group multiple command calls into a single one, given that those commands' IDs are contiguous. For example, a call with command header 0x802F011C (3 parameters total) is equivalent to a call to commands 0xF011C with parameter 0, 0xF011D with parameter 1 and 0xF011E with parameter 2. It is unknown how this feature behaves when used with commands that have a variable number of parameters.

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 also used elsewhere for beginning rendering of mesh(es) 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	float24	VIEWPORT_WIDTH. See command set 0x000F0041.
0x000F0042	float32	VIEWPORT_WIDTH_INV. See command set 0x000F0041.
0x000F0043	float24	VIEWPORT_HEIGHT. See command set 0x000F0041.
0x000F0044	float32	VIEWPORT_HEIGHT_INV. See command set 0x000F0041.
0x801F004D		See command set 0x801F004D.
0x000F0068	u32	VIEWPORT Y/X. See command set 0x000F0041.
0x000F006D		See command set 0x801F004D.
0x000F006E	u32	See command set 0x000F0111.
0x00010080	u32	See command set 0x00030080.
0x00030080	u32	See command set 0x00030080.
0x00040080	u32	See command set 0x00030080.
0x809F0081		This is used to set the current texture info used for rendering, see command set 0x809F0081.
0x000F008E	u32 color type	This command sets the texture color type, see command set 0x809F0081.
0x805F0091		This sets current texture info, see command 0x805F0091.
0x805F0099		This sets current texture info, see command 0x805F0099.
0x800F00C3	val<<24	Val is usually 0xFF or 0x00, however 0x00-0xFF is valid as well. This is alpha-blending related?
0x800F00CB	val<<24	Val is usually 0xFF or 0x00, however 0x00-0xFF is valid as well. This is alpha-blending related?
0x80XF00C0		See command set 0x80XF00C0.
0x800F00C4		See command set 0x80XF00C0.
0x80XF00C8		See command set 0x80XF00C0.
0x800F00CC		See command set 0x80XF00C0.
0x80XF00D0		See command set 0x80XF00C0.
0x800F00D4		See command set 0x80XF00C0.
0x80XF00D8		See command set 0x80XF00C0.
0x800F00DC		See command set 0x80XF00C0.
0x80XF00F0		See command set 0x80XF00C0.
0x800F00F4		See command set 0x80XF00C0.
0x80XF00F8		See command set 0x80XF00C0.
0x800F00FC		See command set 0x80XF00C0.
0x000100E0	Normally value zero.	Unknown, fragment related?
0x000500E0		See command set 0x000500E0.
0x000F00E1		See command set 0x000500E0.
0x000F00E6	Value zero	See command set 0x000F00E6.
0x000F00E8		See command set 0x000F00E6.
0x00020100	u32, value is 0x00E40100	See command set 0x00020100.
0x000D0100	0x00E40000 | val.	Val0 = unknown, val1 = unknown, val3 = unknown. The default val used here is 0.
0x000F0101	u32	See command set 0x00020100.
0x000F0103		See command set 0x00020100.
0x000F0104	u32	glAlphaFunc()
0x00010107		See command set CmdID 0x00010107.
0x00020107		See command set CmdID 0x00010107.
0x00030107		See command set CmdID 0x00030107.
0x000F0116	u32	DEPTHBUFFER FORMAT. See command set 0x000F0111.
0x000F0117	u32	COLORBUFFER FORMAT/PIXEL. See command set 0x000F0111.
0x000F011C	Physical address>>3	DEPTHBUFFER ADDRESS. See command set 0x000F0111.
0x000F011D	Physical address>>3	COLORBUFFER ADDRESS. See command set 0x000F0111.
0x000F011E	u32	COLORBUFFER HEIGHT/WIDTH. See command set 0x000F0111.
0x803F0112		?
0x826F0200		See command set 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 glDrawElements().
0x000F0228	u32 total elements in the array to use for rendering.	See command set glDrawElements().
0x803F0232		See command set 0x826F0200.
0x0002025E	u32, val<<8.	This sets the GL rendering mode, see command set 0x826F0200.
0x000F02B0	u32, value is 0x7FFF0000 | val.	Texture related?
0x801F02BB		See command set 0x826F0200.
0x000F02BA	0x7FFF0000 | entrypoint offset	Sets the entrypoint offset for the shader program
0x000F02C0	0x80000000 | Type	This is used immediately before CmdID 0xXXXF02C1. This type field controls the command parameter buffer type. This command can also be used to send over (float24 only ?) data directly, without using 0xXXXF02C1. In that case, the first parameter is still Type but with bit 31 not set; the actual data follows.
0xXXXF02C1	First word in the first entry	A list of entries follow this command.
0x000F02CB	Value 0x0 ?	This is used immediately before CmdID 0xXXXF02CC. It is used to indicate that shader program data will follow.
0xXXXF02CC	First word of shader program data chunk.	This command is used to transfer shader program data (as the parameter data). It can be called multiple times in a row if the shader program is too big to fit into a single call.
0x000F02BF	Value 0x1 ?	This is used immediately after a set of CmdID 0xXXXF02CC. It is used to indicate that shader program data transfer is complete.
0x000F02D5	Value 0x0 ?	This is used immediately before CmdID 0xXXXF02d6.
0xXXXF02D6	First entry.	This is used to send over the shader program operand descriptor table.
0x000F004F	Number of shader output attributes	Sets number of shader output attributes
0x000F0050	First entry	This command is used to setup shader output registers. The n-th word-long entry is a map of the (n*2)-th output register's components. Each byte of each entry corresponds to where a component is mapped. Value 0x1F indicates that the corresponding component is unused.

Command Sets

glDrawElements()

See GPU GL Arrays.

glClear() / glClearColor()

The GPU does not have dedicated commands for clearing the color buffer, therefore applications implement color buffer clearing by rendering a quad. Applications normally store this vertex and color array in the GSP application heap.

CmdID 0x809F0081

This sets current texture info, see GPU textures.

CmdID 0x00030080

Command Index	CommandID	Parameter	Description
0	0x00030080	0x11000 | val, where only bits 2-1 are used in val.	bit0 enables/disables texturing
0	0x00040080	Same value as CmdID 0x00030080.	?
0	0x00010080	Same value as CmdID 0x00030080.	bit0 enables/disables texturing

CmdID 0x80XF00C0

Command Index	CommandID	Parameter	Description
0	0x802F0000 | SlotCmdID
1	0x800F0000 | SlotCmdID + 4

This is used for glTexEnv(), for the slot indicated by the CmdID. There's a total of 6 slots, where each slot corresponds to the following u16 CmdIDs: 0xC0, 0xC8, 0xD0, 0xD8, 0xF0, 0xF8.

CmdID 0x000500E0

Command Index	CommandID	Parameter	Description
0	0x000500E0	5 | val<<16, where val is 0 or 1.	Val0 = enable, val1 = disable.
1	0x000F00E1		This specifies a color.

This is usually used immediately after command set glDrawElements(). This is used to specify a color used for blending?

CmdID 0x000F00E6

Command Index	CommandID	Parameter	Description
0	0x000F00E6	Value 0	?
1	0x000F00E8

This is usually the last command set used for rendering a mesh, when command set 0x000500E0 was used. This command set is used immediately after command set 0x000500E0.

CmdID 0x00020100

Command Index	CommandID	Parameter	Description
0	0x00020100	Value 0x00E40100	?
1	0x000F0101	0x01010000 when disabled?	?
2	0x000F0103	This is set to zero when the Cmd 0x000F0101 parameter is value 0x01010000.	?

This is fragment related?

CmdID 0x801F004D

Command Index	CommandID	Parameter	Description
0	0x801F004D		glDepthRange()
1	0x000F006D	0 = unknown, 1 = unknown.	Value zero causes the mesh to not be rendered.

CmdID 0x000F0041

Command Index	CommandID	Parameter	Description
0	0x000F0041	float	This corresponds to the framebuffer width.
1	0x000F0043	float	This parameter value is calculated the same way as the CmdID 0x000F0041 parameter, except the framebuffer height is used instead.
2	0x000F0042	float	This corresponds to the framebuffer width.
3	0x000F0044	float	This parameter value value is calculated the same way as the CmdID 0x000F0042 parameter, except the framebuffer height is used instead.
4	0x000F0068	u32	This sets the X/Y coordinates used for glViewport().

This command set initializes the projection matrix. This command set is used twice when beginning rendering for each screen. The framebuffer width used here for the main screen is 240, however this is 480 with stereoscopy enabled for the second time this command set is used.

CmdID 0x000F0111

Command Index	CommandID	Parameter	Description
0	0x000F0111	Value 1
1	0x000F0110	Value 1
2	0x000F0117	Bits15-0 = unk, 31-16 = unk.	Unknown, normally the input parameter is value 0x2.
3	0x000F011D	Physical address>>3	This initializes the framebuffer address used for rendering, this framebuffer is used for the input framebuffer with GX command 3 and 4. This command is used immediately after CmdID 0x000F0117.
4	0x000F0116		?
5	0x000F011C	Physical address>>3	Unknown, normally this address is located in VRAM.
6	0x000F011E	(((h-1)&0xFFF)<<12)|(w&0xFFF)	This sets the width and height for the framebuffer used for rendering. Therefore this is glViewport(), x/y are specified by CmdID 0x000F0068.
7	0x000F006E	Same input parameter value as CmdID 0x000F011E.

This command set is normally used after the two 0x000F0041 command sets.

CmdID 0x00030107

Command Index	CommandID	Parameter	Description
0	0x00030107
1	0x00080126	type<<24

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

CmdID 0x00010107

Command Index	CommandID	Parameter	Description
0	0x00010107	Same format as CmdID 0x00030107.
1	0x00080126	type<<24
0	0x00020107	Same value as CmdID 0x00010107.

Parameter format for CmdIDs 0x00030107, 0x00020107, and 0x00010107

Bit	Description
0	0 = disable GL_DEPTH_TEST, 1 = enable GL_DEPTH_TEST
3-1	Unused?
7-4	Test function
11-8	?
12	?
31-13	Unused

Alpha function values

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

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

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

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 dimensions used with GX command 3 and 4.

Parameter value format for CmdID 0x000F0068

Bit	Description
15-0	X
31-16	Y

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

Parameter structure for CmdID 0x804F00C0

Index Word	Description
0	Value 0xFFF0FFF / 0x0
1	Value 0x0
2	Value 0x0
3	Value 0xFFFFFFFF
4	Value 0x0

This individual command is used instead of the 0x80XF00C0 command set when none of the associated rendering parameters for this slot are set.

Parameter structure for CmdID 0x802F00C0

Index Word	Description
0	Param0
1	Param1
2	Param2

See command set 0x80XF00C0.

Param0 format for CmdID 0x802F00C0

Bit	Description
3-0	See below values.(Field0 index0)
7-4	See below values.(Field0 index1)
11-8	See below values.(Field0 index2)
15-12	Unused
19-16	See below values.(Field1 index0)
23-20	See below values.(Field1 index1)
27-24	See below values.(Field1 index2)
31-28	Unused

Param0 values for CmdID 0x802F00C0

Value	GL type
0x0	GL_PRIMARY_COLOR
0x1	?
0x2	?
0x3	GL_TEXTURE0
0x4	GL_TEXTURE1
0x5	GL_TEXTURE2
0x6	GL_TEXTURE3
0xC-0x7	GL_PRIMARY_COLOR
0xD	?
0xE	GL_CONSTANT
0xF	GL_PREVIOUS

Param1 format for CmdID 0x802F00C0

Bit	Description
3-0	See below values for field0.(Index0)
7-4	See below values for field0.(Index1)
11-8	See below values for field0.(Index2)
15-12	See below values for field1.(Index0)
19-16	See below values for field1.(Index1)
23-20	See below values for field1.(Index2)
31-24	Unused

This specifies the pname for glTexEnv().

Param1 field0 values for CmdID 0x802F00C0

Value	GL type
0x0	GL_SRC_COLOR
0x1	GL_ONE_MINUS_SRC_COLOR
0x2	GL_SRC_ALPHA
0x3	GL_ONE_MINUS_SRC_ALPHA
0x4	GL_SRC0_RGB
0x5	?
0x6	GL_SRC_COLOR
0x7	GL_SRC_COLOR
0x8	GL_SRC1_RGB
0x9	?
0xA	GL_SRC_COLOR
0xB	GL_SRC_COLOR
0xC	GL_SRC2_RGB
0xD	?

Param1 field1 values for CmdID 0x802F00C0

Value	GL type
0x0	GL_SRC_ALPHA
0x1	GL_ONE_MINUS_SRC_ALPHA
0x2	GL_SRC0_RGB
0x3	?
0x4	GL_SRC1_RGB
0x5	?
0x6	GL_SRC2_RGB
0x7	?

Param2 format for CmdID 0x802F00C0

Bit	Description
15-0	See below field0 values.
31-16	See below field1 values.

This is used to specify the param for glTexEnv(..., ..., param).

Param2 field0 values for CmdID 0x802F00C0

Value	GL type
0x0	GL_REPLACE
0x1	GL_MODULATE
0x2	GL_ADD
0x3	GL_ADD_SIGNED
0x4	GL_INTERPOLATE
0x5	GL_SUBTRACT
0x6	GL_DOT3_RGB
0x7	GL_DOT3_RGBA
0x8	?
0x9	?

Param2 field1 values for CmdID 0x802F00C0

Value	GL type
0x0	GL_REPLACE
0x1	GL_MODULATE
0x2	GL_ADD
0x3	GL_ADD_SIGNED
0x4	GL_INTERPOLATE
0x5	GL_SUBTRACT
0x6	GL_REPLACE
0x7	GL_DOT3_RGB
0x8	?
0x9	?

Parameter value format for CmdID 0x800F00C4

Bit	Description
15-0	Valid values: 0=unknown, 1=unknown, 2=unknown.
31-16	Same format as bits15-0.

See command set 0x80XF00C0.

Parameter value format for CmdID 0x000F00E1

Bit	Description
7-0	Red component
15-8	Green component
23-16	Blue component
31-24	Unused

Parameter value format for CmdID 0x000F0101

This command controls alphablending. To disable alphablending, the value is set to 0x01010000.

Bit	Description
7-0	Color blend equation
15-8	Alpha blend equation
19-16	Color source factor
23-20	Color destination factor
27-24	Alpha source factor
31-28	Alpha destination factor

Blend equation values:

Value	Description
0	GL_FUNC_ADD
1	GL_FUNC_SUBTRACT
2	GL_FUNC_REVERSE_SUBTRACT
3	GL_MIN
4	GL_MAX

Source/destination factor values:

Value	Description
0	GL_ZERO
1	GL_ONE
2	GL_SRC_COLOR
3	GL_ONE_MINUS_SRC_COLOR
4	GL_DST_COLOR
5	GL_ONE_MINUS_DST_COLOR
6	GL_SRC_ALPHA
7	GL_ONE_MINUS_SRC_ALPHA
8	GL_DST_ALPHA
9	GL_ONE_MINUS_DST_ALPHA
10	GL_CONSTANT_COLOR
11	GL_ONE_MINUS_CONSTANT_COLOR
12	GL_CONSTANT_ALPHA
13	GL_ONE_MINUS_CONSTANT_ALPHA
14	GL_SRC_ALPHA_SATURATE

Parameter structure for CmdID 0x801F004D

Index Word	Description
0	float far
1	float near

This is glDepthRange().

Parameter structure for CmdID 0x000F00E8

Index Word	Description
0x7D-0x00	Usually value 0x00FFE000.
0x7E	Usually value 0x00FFFEE6?
0x7F	Usually value 0x00DCD919?

Parameter structure for CmdID 0x803F0112

Index Word	Description
0	0x0 = unknown, 0xF = unknown. Only bits 3-0 are used.(Values 0x1-0xF all have the same effect)
1	0x0 = unknown, 0xF = unknown. Only bits 3-0 are used.
2	0x0 = unknown, 0x2 = unknown. Only bits 1-0 are used.(Values 0x1-0x3 all have the same effect)
3	0x0 = unknown, 0x2 = unknown. Only bits 1-0 are used.(Values 0x1-0x3 all have the same effect)

Entries for CmdID 0xXXXF02C1

Index Word	Description
0	float, the GPU handles this as the 4th word.
1	float, the GPU handles this as the 3rd word.
2	float, the GPU handles this as the 2nd word.
3	float, the GPU handles this as the 1st word.

The below entry structure info is in the raw order used for the command, not the order used by the GPU.

Color Entry

Index Word	Description
0	float Red component
1	float Blue component
2	float Green component
3	float Alpha

Lighting Color Entry

Index Word	Description
0	float Alpha
1	float Blue component
2	float Green component
3	float Red component

Types for CmdID 0x000F02C0

The 0x000F02C0/0x000F02C1 is actually used as a generic way to set uniforms, regardless of what they represent. 0x000F02C0's parameter represents the ID of the destination GPU register (0x0 is c0, 0x1 is c1 etc). As such, the meaning of the data being sent over is entirely dependant on the shader currently in use. The values below may be "default" values used by Nintendo's openGL implementation.

Value	Entries per chunk	Description
0x00	4	This specifies 16-floats for a 4x4 matrix, used for glLoadMatrix() for the projection matrix.
0x04	4	This specifies a 4x4 matrix, used for glLoadMatrix() for the model-view matrix. This is usually an identity matrix.
0x08	2	Sets the color.
0x0A	4	Specifies a 4x4 matrix, used for glLoadMatrix() for the texture matrix.(Index0)
0x0E	3	Specifies a 4x3 texture matrix.(Index1)
0x11	3	Specifies a 4x3 texture matrix.(Index2)
0x14	<=30	Used to specify a 4xN matrix, where N is the total CmdID 0xXXXF02C1 entries. This is glMultMatrix() for the model-view matrix, except the input matrix is 4xN instead of 4x4.
0x4C	4	This specifies a 4x4 float matrix.
0x50, 0x53, and 0x56	1	This specifies the GL_LIGHT0-2 color for GL_AMBIENT?
0x51, 0x54, and 0x57	1	This specifies the GL_LIGHT0-2 color for GL_DIFFUSE?
0x52, 0x55, and 0x58	1	This specifies the GL_LIGHT0-2 color for GL_SPECULAR?
0x59	1	Unknown, the entry data is floats converted from s32s. Usually each entry word is zeros.
0x5A	2	Color related?
0x5C	1	?

The matrices for types 0x00 and 0x04 use row-major order, instead of column-major order.