gba_multiboot - GameBoy Advance Multiboot

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Ken Kaarvik / Mbed 2 deprecated gba_multiboot

GameBoy Advance Multiboot

main.cpp@0:b046e1b46227, 2010-11-13 (annotated)

Committer:: kek
Date:: Sat Nov 13 10:42:21 2010 +0000
Revision:: 0:b046e1b46227

Who changed what in which revision?

User	Revision	Line number	New contents of line
kek	0:b046e1b46227	1	// mbed GBA Loader - Boot up a GameBoy Advance using Multiboot (no cart req.)
kek	0:b046e1b46227	2	//
kek	0:b046e1b46227	3	// Ken Kaarvik kkaarvik@yahoo.com
kek	0:b046e1b46227	4	// Nov 13, 2010
kek	0:b046e1b46227	5	//
kek	0:b046e1b46227	6	// mbed gba serial port
kek	0:b046e1b46227	7	// 1-0V 6-0V
kek	0:b046e1b46227	8	// p5-mosi 3-SI
kek	0:b046e1b46227	9	// p6-miso 2-SO
kek	0:b046e1b46227	10	// p7-sck 5-SC
kek	0:b046e1b46227	11	// p8-input 1-3V3
kek	0:b046e1b46227	12	//
kek	0:b046e1b46227	13	// p15-analogIn 0-3V3 test voltage pot
kek	0:b046e1b46227	14	// p16-analogIn 0-3V3 test voltage pot
kek	0:b046e1b46227	15	//
kek	0:b046e1b46227	16	// note: the GBA does not power the mbed
kek	0:b046e1b46227	17	//
kek	0:b046e1b46227	18	// The GBA file that you wish to load into the GBA is stored on the mbed's local file system.
kek	0:b046e1b46227	19	// (Just drag and drop it onto the drive where mbed is located.)
kek	0:b046e1b46227	20	// The GBA can be multibooted with a maximum file size of 256kB (the mbed shows up on my
kek	0:b046e1b46227	21	// computer as a flash drive with 2MB of memory, room for several GBA files!)
kek	0:b046e1b46227	22	//
kek	0:b046e1b46227	23	// Apply power to the mbed (or reset) before turning on the GBA.
kek	0:b046e1b46227	24	//
kek	0:b046e1b46227	25
kek	0:b046e1b46227	26	#include "mbed.h"
kek	0:b046e1b46227	27
kek	0:b046e1b46227	28	Serial pc(USBTX, USBRX); //debug info - see raw data being transferred back and forth as GBA is booting
kek	0:b046e1b46227	29
kek	0:b046e1b46227	30	SPI spi(p5, p6, p7); // mosi, miso, sclk
kek	0:b046e1b46227	31
kek	0:b046e1b46227	32	LocalFileSystem local("local");
kek	0:b046e1b46227	33
kek	0:b046e1b46227	34	DigitalIn gba_present(p8);
kek	0:b046e1b46227	35
kek	0:b046e1b46227	36	DigitalOut myled1(LED1); //used for my demo program (volt4.gba)
kek	0:b046e1b46227	37	DigitalOut myled2(LED2); //used for my demo program (volt4.gba)
kek	0:b046e1b46227	38	DigitalOut myled3(LED3); //used for my demo program (volt4.gba)
kek	0:b046e1b46227	39	DigitalOut myled4(LED4); //used for my demo program (volt4.gba)
kek	0:b046e1b46227	40	AnalogIn voltmeter1(p15); //used for my demo program (volt4.gba)
kek	0:b046e1b46227	41	AnalogIn voltmeter2(p16); //used for my demo program (volt4.gba)
kek	0:b046e1b46227	42
kek	0:b046e1b46227	43	unsigned long read_from_gba;
kek	0:b046e1b46227	44	//unsigned long test_counter;
kek	0:b046e1b46227	45
kek	0:b046e1b46227	46	long writeSPI32bits(long write32)
kek	0:b046e1b46227	47	{
kek	0:b046e1b46227	48	pc.printf("0x%08x ",write32);
kek	0:b046e1b46227	49	long read32 = (spi.write(write32>>16))<<16;
kek	0:b046e1b46227	50	read32 = (spi.write(write32))\|read32;
kek	0:b046e1b46227	51	pc.printf("0x%08x ",read32);
kek	0:b046e1b46227	52	return read32;
kek	0:b046e1b46227	53	}
kek	0:b046e1b46227	54
kek	0:b046e1b46227	55	long writeSPI32bits_nodebug(long write32)
kek	0:b046e1b46227	56	{
kek	0:b046e1b46227	57	long read32 = (spi.write(write32>>16))<<16;
kek	0:b046e1b46227	58	read32 = (spi.write(write32))\|read32;
kek	0:b046e1b46227	59	return read32;
kek	0:b046e1b46227	60	}
kek	0:b046e1b46227	61
kek	0:b046e1b46227	62	int main()
kek	0:b046e1b46227	63	{
kek	0:b046e1b46227	64	// Setup the spi for 8 bit data, high steady state clock,
kek	0:b046e1b46227	65	// second edge capture, with a 100 kHz clock rate
kek	0:b046e1b46227	66	spi.format(16,3);
kek	0:b046e1b46227	67	spi.frequency(100000);
kek	0:b046e1b46227	68
kek	0:b046e1b46227	69	pc.printf("\n\n\r.....GBA Multiboot Hack......\n\n\r");
kek	0:b046e1b46227	70	if (gba_present)
kek	0:b046e1b46227	71	pc.printf(".....Please turn off GBA.....\n\r");
kek	0:b046e1b46227	72	while(gba_present);
kek	0:b046e1b46227	73	wait(0.2);
kek	0:b046e1b46227	74	if(!gba_present)
kek	0:b046e1b46227	75	pc.printf(".....Please turn on GBA......\n\r");
kek	0:b046e1b46227	76	while(!gba_present);
kek	0:b046e1b46227	77	wait(0.2);
kek	0:b046e1b46227	78	pc.printf(".....GBA power up detected!..\n\r");
kek	0:b046e1b46227	79
kek	0:b046e1b46227	80	FILE fp = fopen("/local/volt4.gba", "rb"); //**change .gba file here***
kek	0:b046e1b46227	81	pc.printf(".....Opening GBA file readonly\r\n");
kek	0:b046e1b46227	82
kek	0:b046e1b46227	83	fseek(fp, 0L, SEEK_END); //get *.gba file length
kek	0:b046e1b46227	84	long gba_file_length= ftell(fp);
kek	0:b046e1b46227	85	gba_file_length = (gba_file_length+0x0f)&0xfffffff0; //align length to xfer to 16
kek	0:b046e1b46227	86	fseek(fp, 0L, SEEK_SET);
kek	0:b046e1b46227	87	pc.printf(".....GBA file length 0x%08x\r\n\n",gba_file_length);
kek	0:b046e1b46227	88	pc.printf("MBED(mstr) GBA(slave) \r\n\n");
kek	0:b046e1b46227	89
kek	0:b046e1b46227	90	while(read_from_gba!=0x72026202)
kek	0:b046e1b46227	91	{
kek	0:b046e1b46227	92	wait(0.01);
kek	0:b046e1b46227	93	read_from_gba = writeSPI32bits(0x00006202);
kek	0:b046e1b46227	94	pc.printf(" ;Looking for GBA\r\n");
kek	0:b046e1b46227	95	}
kek	0:b046e1b46227	96
kek	0:b046e1b46227	97	read_from_gba = writeSPI32bits(0x00006202);
kek	0:b046e1b46227	98	pc.printf(" ;Found GBA\r\n");
kek	0:b046e1b46227	99
kek	0:b046e1b46227	100	read_from_gba = writeSPI32bits(0x00006102);
kek	0:b046e1b46227	101	pc.printf(" ;Recognition ok\r\n");
kek	0:b046e1b46227	102
kek	0:b046e1b46227	103	int i;
kek	0:b046e1b46227	104	for(int Counter=0;Counter<=0x5f;Counter++)
kek	0:b046e1b46227	105	{
kek	0:b046e1b46227	106	i = getc(fp); //Read in 16 bits of .gba file
kek	0:b046e1b46227	107	i = getc(fp)<<8\|i; //Read in 16 bits of .gba file
kek	0:b046e1b46227	108
kek	0:b046e1b46227	109	read_from_gba = writeSPI32bits_nodebug(0x0000ffff&i);
kek	0:b046e1b46227	110	// pc.printf(" ;send header a\r\n");
kek	0:b046e1b46227	111	}
kek	0:b046e1b46227	112
kek	0:b046e1b46227	113	read_from_gba = writeSPI32bits(0x00006200);
kek	0:b046e1b46227	114	pc.printf(" ;Transfer of header data complete\r\n");
kek	0:b046e1b46227	115
kek	0:b046e1b46227	116	read_from_gba = writeSPI32bits(0x00006202);
kek	0:b046e1b46227	117	pc.printf(" ;Exchange master/slave info again\r\n");
kek	0:b046e1b46227	118
kek	0:b046e1b46227	119	read_from_gba = writeSPI32bits(0x000063d1);
kek	0:b046e1b46227	120	pc.printf(" ;Send palette data\r\n");
kek	0:b046e1b46227	121
kek	0:b046e1b46227	122	read_from_gba = writeSPI32bits(0x000063d1);
kek	0:b046e1b46227	123	pc.printf(" ;Send palette data, receive 0x73hh****\r\n");
kek	0:b046e1b46227	124
kek	0:b046e1b46227	125	long m = ((read_from_gba&0x00ff0000)>>8)+0xffff00d1;
kek	0:b046e1b46227	126	long hh = ((read_from_gba&0x00ff0000)>>16)+0xf;
kek	0:b046e1b46227	127
kek	0:b046e1b46227	128	writeSPI32bits((((read_from_gba>>16)+0x0000000f)&0xff)\|0x00006400);
kek	0:b046e1b46227	129	pc.printf(" ;Send handshake data\r\n");
kek	0:b046e1b46227	130
kek	0:b046e1b46227	131	read_from_gba = writeSPI32bits((gba_file_length-0x190)/4);
kek	0:b046e1b46227	132	pc.printf(" ;Send length info, receive seed 0xcc**\r\n");
kek	0:b046e1b46227	133
kek	0:b046e1b46227	134	long c = 0x0000c387;
kek	0:b046e1b46227	135	long f = ((((read_from_gba&0x00ff0000)>>8)+hh)+0x00)\|0xffff0000;
kek	0:b046e1b46227	136
kek	0:b046e1b46227	137	pc.printf(" ;Send encrypted data (takes too long to show it all!)\r\n");
kek	0:b046e1b46227	138
kek	0:b046e1b46227	139	unsigned int gba_file_location = 0xc0;
kek	0:b046e1b46227	140	while(gba_file_location<gba_file_length)
kek	0:b046e1b46227	141	{
kek	0:b046e1b46227	142	long gba_data = getc(fp); //Read in 32 bits of .gba file
kek	0:b046e1b46227	143	gba_data = getc(fp)<<8\|gba_data;
kek	0:b046e1b46227	144	gba_data = getc(fp)<<16\|gba_data;
kek	0:b046e1b46227	145	gba_data = getc(fp)<<24\|gba_data;
kek	0:b046e1b46227	146
kek	0:b046e1b46227	147	long gba_data2 = gba_data;
kek	0:b046e1b46227	148
kek	0:b046e1b46227	149	for(int bit=0;bit<32;bit++)
kek	0:b046e1b46227	150	{
kek	0:b046e1b46227	151	if((c^gba_data)&0x01)
kek	0:b046e1b46227	152	c =(c>>1)^0x0000c37b;
kek	0:b046e1b46227	153	else
kek	0:b046e1b46227	154	c = c>>1;
kek	0:b046e1b46227	155	gba_data = gba_data>>1;
kek	0:b046e1b46227	156	}
kek	0:b046e1b46227	157	m = (0x6f646573*m)+1;
kek	0:b046e1b46227	158	writeSPI32bits_nodebug(gba_data2^((~(0x02000000+gba_file_location))+1)^m^0x43202f2f);//This line or next two
kek	0:b046e1b46227	159	// writeSPI32bits(gba_data2^((~(0x02000000+gba_file_location))+1)^m^0x43202f2f); //***Uncomment two line to see all data being transfered***
kek	0:b046e1b46227	160	// pc.printf(" ;\n\r"); //***Uncomment two line to see all data being transfered***
kek	0:b046e1b46227	161	gba_file_location=gba_file_location+4;
kek	0:b046e1b46227	162	}
kek	0:b046e1b46227	163
kek	0:b046e1b46227	164	for(int bit=0;bit<32;bit++)
kek	0:b046e1b46227	165	{
kek	0:b046e1b46227	166	if((c^f)&0x01)
kek	0:b046e1b46227	167	c =(c>>1)^0x0000c37b;
kek	0:b046e1b46227	168	else
kek	0:b046e1b46227	169	c = c>>1;
kek	0:b046e1b46227	170	f = f>>1;
kek	0:b046e1b46227	171	}
kek	0:b046e1b46227	172
kek	0:b046e1b46227	173	while (writeSPI32bits(0x00000065)!=0x00750065)
kek	0:b046e1b46227	174	{
kek	0:b046e1b46227	175	pc.printf(" ;Wait for GBA to respond with CRC\n\r");
kek	0:b046e1b46227	176	}
kek	0:b046e1b46227	177
kek	0:b046e1b46227	178	pc.printf(" ;GBA ready with CRC\n\r");
kek	0:b046e1b46227	179
kek	0:b046e1b46227	180	writeSPI32bits(0x00000066);
kek	0:b046e1b46227	181
kek	0:b046e1b46227	182	pc.printf(" ;Let's exchange CRC!\n\r");
kek	0:b046e1b46227	183
kek	0:b046e1b46227	184	writeSPI32bits(c);
kek	0:b046e1b46227	185
kek	0:b046e1b46227	186	pc.printf(" ;CRC ...hope they match!\n\r");
kek	0:b046e1b46227	187	pc.printf(" ;All done!\n\r\n");
kek	0:b046e1b46227	188
kek	0:b046e1b46227	189	fclose(fp); //**Done with multiboot******************************************************
kek	0:b046e1b46227	190
kek	0:b046e1b46227	191	//**Following is code to talk to GBA running my custom program (volt4.gba)***
kek	0:b046e1b46227	192
kek	0:b046e1b46227	193	while(1) //read in analog values on p15 and p16, only use 9 bits from both, pack up and send to GBA
kek	0:b046e1b46227	194	{
kek	0:b046e1b46227	195	read_from_gba = writeSPI32bits((voltmeter1.read_u16()>>7)\|((voltmeter2.read_u16()&0xff80)<<2));
kek	0:b046e1b46227	196	pc.printf("\r");
kek	0:b046e1b46227	197	read_from_gba =(~read_from_gba)&0x3ff;
kek	0:b046e1b46227	198	myled1 = (read_from_gba & 0x1); //turn on led1 when "A" button on GBA is pressed
kek	0:b046e1b46227	199	myled2 = (read_from_gba & 0x2); //B
kek	0:b046e1b46227	200	myled3 = (read_from_gba & 0x4); //Select
kek	0:b046e1b46227	201	myled4 = (read_from_gba & 0x8); //Start
kek	0:b046e1b46227	202	}
kek	0:b046e1b46227	203
kek	0:b046e1b46227	204	}

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	13 Nov 2010
Imports:	29
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	3

main.cpp@0:b046e1b46227, 2010-11-13 (annotated)

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