babelfish/gecko.c
2011-06-20 16:11:10 -07:00

106 lines
2.1 KiB
C

/*
babelfish - self-propagating Just-In-Time IOS patcher
Copyright (C) 2008-2011 Haxx Enterprises <bushing@gmail.com>
This code is licensed to you under the terms of the GNU GPL, version 2;
see file COPYING or http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt
This code lives at http://gitweb.bootmii.org/?p=babelfish.git
*/
#include "types.h"
#include "utils.h"
#include "hollywood.h"
#include "gecko.h"
/* some of this code is redundant with that in vectors.s */
static int gecko_active = 0;
static u32 _gecko_command(u32 command)
{
u32 i;
// Memory Card Port B (Channel 1, Device 0, Frequency 3 (32Mhz Clock))
write32(EXI1_CSR, 0xd0);
write32(EXI1_DATA, command);
write32(EXI1_CR, 0x19);
while (read32(EXI1_CR) & 1);
i = read32(EXI1_DATA);
write32(EXI1_CSR, 0);
return i;
}
static u32 _gecko_sendbyte(char sendbyte)
{
u32 i = 0;
i = _gecko_command(0xB0000000 | (sendbyte<<20));
if (i&0x04000000)
return 1; // Return 1 if byte was sent
return 0;
}
static u32 _gecko_checksend(void)
{
u32 i = 0;
i = _gecko_command(0xC0000000);
if (i&0x04000000)
return 1; // Return 1 if safe to send
return 0;
}
int gecko_isalive(void)
{
u32 i;
i = _gecko_command(0x90000000);
if ((i&0xFFFF0000) != 0x04700000)
return 0;
return 1;
}
void gecko_init(void)
{
write32(EXI0_CSR, 0);
write32(EXI1_CSR, 0);
write32(EXI2_CSR, 0);
write32(EXI0_CSR, 0x2000);
write32(EXI0_CSR, 3<<10);
write32(EXI1_CSR, 3<<10);
gecko_active = 0;
if(gecko_isalive())
gecko_active = 1;
}
int gecko_putc(int c) {
if (!gecko_active) return -1;
int tries = 10000; // about 200ms of tries; if we fail, fail gracefully instead of just hanging
// this makes CCC demos less embarassing
if((read32(HW_EXICTRL) & EXICTRL_ENABLE_EXI) == 0)
return 0;
if(_gecko_checksend()) {
if(!_gecko_sendbyte(c))
return 0;
} else {
// if gecko is hung, time out and disable further attempts
// only affects gecko users without an active terminal
if(tries-- == 0) {
gecko_active = 0;
return 0;
}
}
return 1;
}
int gecko_puts(const char *s) {
int bytes_written = 0;
while(*s) {
if (!gecko_putc(*s++)) break;
bytes_written++;
}
return bytes_written;
}