This is not correct. Nintendont does not use MIOS at all, but does have access to the gamecube hardware that is present in the Wii, including the MX chip. As I already said, you need to remove the calls in loader/source/main.c to these functions:
extern void __SYS_ReadROM(void *buf,u32 len,u32 offset);
extern u32 __SYS_GetRTC(u32 *gctime);
extern syssram* __SYS_LockSram();
extern u32 __SYS_UnlockSram(u32 write);
extern u32 __SYS_SyncSram(void);
I think the Sram functions are only used to alter the video mode and language, so if you aren't forcing those, you can probably remove the code there. You can replace the GetRTC call with a hard-coded value, or just live with very wrong dates. Note that games that use the fonts will not display correctly or just won't work unless you load a font file instead of the ROM (you can use Dolphin's font files or the official ones if you've dumped your ROM). Just read the fonts into buf.
Also, note that if you don't have emulated memory cards turned on, any time a game attempts to use one of these functions (reads the fonts, reads the RTC), you will have problems. The emulated memory card setting controls access to all EXI devices in game which includes the MX chip, memory cards, microphones, etc.
