Need some hard notes so I am posting here. This does not mean I am going to get n64 dd emulation running. This is mostly what little bits I can get out of a few people plus debugging the ipl4rom.
:cool: As always, this stuff stays private. :cool:
-- 64 DD Boot (Abnormal instances) --
1) Does SW write test to RDRAM starting at 4MB to 8MB. Consist of two writes. at 1MB intervals & a second at XXX (forgot offset).
2) Sets PI Domain2 registers (domain 1 = rom, domain 2 = dd).
3) Writes 0xAAAA0000 (SW opcode) to 0x05000520 (PC: 0x8027C0E4).
4) Reads (LW opcode) from 0x05000508 (PC: 0x8027BF44).
5) Branch Check
--- Four senarios ATM ---
- 1 - Value in the lower 16bits
.1) Error 41
.2) Constant loop check of the DD Status Register.
- 2 - 0x01000000
- 3 - 0x01020000
- 4 - 0x00000000
.1) Writes 0x00000000 (SW opcode) to 0x05000500 (PC: 0x8027C0E4).
.2) Writes 0x00140000 (SW opcode) to 0x05000508 (PC: 0x8027C0E4). ?? SET_RTC_CMD
.3) No more checks of DD Registers ??
-- 64 DD Registers (known) --
0x05000500 - Data
0x05000508 - Command / Status (?)
0x05000520 - Hardware Reset
-- Assumptions --
The IPL4ROM uses Fast3D Ext (modified) or F3DEX1.0 Microcode.
-- Additional info --
Was told the system time is stored in BCD format.
http://www.danbbs.dk/~erikoest/bcd.htm
Was told the 64DD tries to read a value from the status after the Hard Reset. If the value is not valid it wont progress to calling to read the RTC.
-- Notes from another forum --
This IPL rom are dumped from retail 64DD.
using GameShark and Hacked GS Utility.
64DD IPL rom are mapped 0xA6000000-0xA63FFFFFFF(0x06000000-0x063FFFFF).
If you want running it on Emulator, change IPL rom header
00000000: 80 27 07 40 -> 80 37 12 40
**Edit**
and replace Offset:00000040-00001000 to other rom that has CIC-NUS-6102/5.
-- Error Code List --
Error 23: The disk drive may have failed or the disk may be defective. http://ksnk.sakura.ne.jp/ddlab/supp/er.html
Error 41: Error communicating with DD. DD not properly connected
Error 44: Expansion Pak Error (Detects only 4MB).
*See images below for error messages in japanese.
-- Monkey64 info --
Monkey64 can currently run the IPL4ROM to an extent but no 3d is rendered. Just 2D. The rom currently gives back an Error Message.
