main.c File Reference

SuperFX (GSU) Hello World — boot diagnostic. More...

#include <snes.h>
#include <snes/superfx.h>

Functions
static u8	hexchar (u8 n)
	Convert a nibble to hex ASCII.
void	launchGSU (void)
	Launch GSU program, wait for completion (defined in gsu_loader.asm).
int	main (void)

Variables
u16	gsu_fmult_test1
u16	gsu_fmult_test2
u16	gsu_result
	GSU R0 result after launchGSU() (set by gsu_loader.asm).
u8	gsu_sram_byte0
u8	gsu_sram_byte1
u16	gsu_sram_word

Detailed Description

SuperFX (GSU) Hello World — boot diagnostic.

Detects the SuperFX coprocessor, launches a minimal GSU program that sets R0 = $CAFE, and reads back the result to verify two-way communication between the SNES CPU and the GSU.

What to Observe

• GSU chip version displayed (VCR register)
• GSU R0 result: $CAFE confirms the GSU executed code correctly
• If no SuperFX hardware: "NOT DETECTED" message

SNES Concepts

• SuperFX (GSU) coprocessor detection and communication
• WRAM stub execution (CPU cannot read ROM while GSU owns the bus)
• SRAM shared memory between SNES CPU and GSU

Modules Used

console, sprite, dma, background, text, superfx

See also

examples/graphics/effects/superfx_bitmap for GSU framebuffer rendering

Function Documentation

hexchar()

u8 hexchar ( u8 n )

static

Convert a nibble to hex ASCII.

launchGSU()

void launchGSU ( void )

extern

Launch GSU program, wait for completion (defined in gsu_loader.asm).

main()

int main

(

void

)

Variable Documentation

gsu_fmult_test1

u16 gsu_fmult_test1

extern

gsu_fmult_test2

u16 gsu_fmult_test2

extern

gsu_result

u16 gsu_result

extern

GSU R0 result after launchGSU() (set by gsu_loader.asm).

gsu_sram_byte0

u8 gsu_sram_byte0

extern

gsu_sram_byte1

u8 gsu_sram_byte1

extern

gsu_sram_word

u16 gsu_sram_word

extern