Disassembly of the iriver H300 original firmware
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.
I have so far disassemled 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:
Some general purpose outputs are set like this when enabling the backlight:
|| GPO0ACT? = 1, GPO1ACT? = 0
|| I don't yet know what these pins do
|| GPOOD0ACT? = inv. PWM, GPOOD0STB? = PWM HiZ
|| The backlight pin is tristated when the device is off
Also, when they turn off the device, they set GPOOD2 and GPOOD3 like this:
|| GPOOD2ACT? = HiZ, GPOOD2STB? = HiZ
|| UDA1380 Reset
|| 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;
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