Disassembly of the iriver H300 original firmware

General

I took the time to start a serious disassembly of the H300 1.30eu iriver firmware to see if I could find out some things about the power management, and the handling of the remote controls.

Progress

I have so far disassembled the boot process up to when the actual firmware code is copied to RAM and started.

Findings so far

Nothing spectacular, but here are a few things that they do and we should:

PCF50606

Some general purpose outputs are set like this when enabling the backlight:

Register	Value	Meaning	Comment
0x39	0x07	GPO0ACT? = 1, GPO1ACT? = 0	I don't yet know what these pins do
0x3a	0x3b	GPOOD0ACT? = inv. PWM, GPOOD0STB? = PWM HiZ	The backlight pin is tristated when the device is off Will recheck this

Also, when they turn off the device, they set GPOOD2 and GPOOD3 like this:

Register	Value	Meaning	Comment
0x3b	0x00	GPOOD2ACT? = HiZ, GPOOD2STB? = HiZ	UDA1380 Reset
0x3c	0x07	GPOOD3ACT? = 0, GPOOD3STB? = HiZ	I don't know what this pin does

For some reason, the application retains the OPMOD settings for the regulators:

IOREGC = (IOREGC & 0xe0) | 0x14;
D1REGC = (D1REGC & 0xe0) | 0x1f;
D2REGC = ((D2REGC & 0xe0) | 0x18) & 0x1f; /* What a silly thing to do... */
D3REGC = (D3REGC & 0xe0) | 0x10;
LPREGC = (LPREGC & 0xe0) | 0x0f;

LCD

This is the sequence they seem to use for turning on and off the LCD:

void lcd_enable(bool on_off)
{
   if(on_off)
   {
      lcd_write_reg(R_DISP_CONTROL1, 0x0061);
      sleep(1);
      lcd_write_reg(R_DISP_CONTROL1, 0x0067);
      sleep(1);
      lcd_write_reg(R_DISP_CONTROL1, 0x0637);
      backlight_on();
   }
   else
   {
      backlight_off();
      lcd_write_reg(R_DISP_CONTROL1, 0x0636);
      sleep(1);
      lcd_write_reg(R_DISP_CONTROL1, 0x0626);
   }
}