[coreboot] Porting to Asus M4A785-M

Juhana Helovuo juhe at iki.fi
Fri Jul 30 12:51:53 CEST 2010

On Thu, 2010-07-29 at 20:14 +0300, Andriy Gapon wrote:
> Juhana Helovuo said the following:
> > Meanwhile, I added call to it8712f_kill_watchdog() , like Rudolf Marek
> > suggested.
> BTW, if it's not too hard, could you please share what value that register
> (IT8712F_CONFIG_REG_WATCHDOG) has before being reset to zero in it8712f_kill_watchdog?
> Thanks!

Ok, but I am not sure how one is supposed to read the Super I/O
registers, since there is only a write routine. I made an educated guess
and wrote a read routine as follows:

Added in superio/ite/it8712f/it8712f_early_serial.c :

static uint8_t it8712f_sio_read(uint8_t ldn, uint8_t index)
        outb(IT8712F_CONFIG_REG_LDN, SIO_BASE);
        outb(ldn, SIO_DATA);
        outb(index, SIO_BASE);
        return inb(SIO_DATA);

uint8_t it8712f_kill_watchdog(void)
        uint8_t prev_config;

        prev_config = it8712f_sio_read(0x07, IT8712F_CONFIG_REG_WATCHDOG);

        /* Kill the Watchdog */
        it8712f_sio_write(0x07, IT8712F_CONFIG_REG_WATCHDOG, 0x00);

        return prev_config;

Then in mainboard/asus/m4a785-m/romstage.c :

        it8712f_enable_serial(0, CONFIG_TTYS0_BASE);
        watchdog_prev_config = it8712f_kill_watchdog(); /* disable watchdog, so it does not reset while still booting */
        printk(BIOS_DEBUG, "cpu_init_detectedx = %08lx \n", cpu_init_detectedx);
        printk(BIOS_DEBUG, "Super I/O Watchdog was killed. Previous WD config was %02x\n",watchdog_prev_config);

The result is:

coreboot-4.0-r5631M Fri Jul 30 21:27:07 EEST 2010 starting...

BSP Family_Model: 00100f62 
*sysinfo range: [000cc000,000cdfa0]
bsp_apicid = 00 
cpu_init_detectedx = 00000000 
Super I/O Watchdog was killed. Previous WD config was 30

Hope this makes sense,
Juhana Helovuo

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