So a few questions to help me understand.
1) There is a hard drive which runs some kind of file system?
Yes, a FAT32 partition, the home sleeve has a USB interface for media management with your own pc.
2) The bin file is copied to the hard drive?
Thats right, utilized as described above
3) There is a flash chip also in the device?
Yes, the socketed 29f040.
4) The flash chip is what runs the device or boots it up?
Yes, the Hitachi CPU (SH7034) is hardwired in mode 7 or PROM mode, it polls the (in this case) 29f040 on power up for its OS code.
5) Do you know what the console prints in terms of operating system or boot loader information/version?
My only interface is the LCD screen (4 line dot matrix) that would only display anything if the code was actually running correctly.
6) Can you boot the device if you do not push 'P'?
Not anymore. Initially, I could still invoke the loader program when I pushed P at power up, but once I screwed the eeprom with my own ineptitude with the external programmer, I can't even run that anymore.
7) Has the flash chip been modified?
Yes, as above
8) Are you able to unroll the bin file with binwalk?
Won't help. I have the source code anyway. Problem is I don't know enough about it to be able to interpret it properly.
9) Do you have reverse engineering skills and/or software?
Sure, coding isn't necessarily one of them, but I am good in lots of other things.
10) Do you have a copy of the beta 11 or whatever the original binary file was?
Yes
11) Do you have the change logs for the binary files?
Not really, even if I did, doubt they would be much help in this case
12) How many hardware configurations are there?
Just a couple but all software compatible, same bins for all versions hardware wise
13) Was the hard drive replaced with compatible configuration and file system?
I've probably put close to 20 different drives into it over the years. Not an issue, this is the first time I lost the eeprom code though.
What I need to establish is exactly how the bin file is positioned, and what the initial code bytes at 0000h are. The location I am pretty sure I know as stated in my original post, the code bytes at the beginning of the ROM memory space are not documented, and may possibly be determined by accurately determining the install routine that runs when the loader program is updated. This is documented in the source code, but I can't make enough sense out of it with my coding skill level to see if those initial bytes are even there. Obviously something needs to be there, the one comment I managed to unearth with the wayback machine refers to it but does not give any specific details about it.
I have the source code, I have the reference materials for the components (CPU & eeprom) I even have the proper compiler environment setup to compile code in a VM, but thats when I hit my wall. I don't know how to snip up pieces of code to generate those initial bytes, over even what to look for to figure it out from here.
Thanks for getting back to me though!