[UPDATE] DOCBoot support for NFTL-based DOC2000

[Zeri Virgo]

 > There is a small (but important) fix to
> memory size detection, which shouldn't affect you since you're not using 
> initrd (I think).
No, you're right - I'm not using initrd.

> There is also a new option in doc_bootstub.h: #define DEBUG_BUILD.  This 
> will print out some interesting info during the "Installing DOCBoot" 
> phase, and wait for a keypress.

--------------------------------------------------------------
Award Modular BIOS v4.51PG, An Energy Star Ally
...
HS-4020 VER:1.4

Cyrix MediaGX With MMX-S CPU at 300MHz
Memory Test :   64000K OK + 1536 shared memory

Award Plug and Play BIOS Extension v1.0A
...
Installing DOCBoot.
doc_seg = 0xD000    setup_seg = 0x2000
int15/88 returns 0xF600    initrd_start = 0x000000
top of low mem = 0x0280k    handler seg = 0x9FC0
   -- Press any key --
--------------------------------------------------------------

...<snip>...
Loading kernel ... page 0x.... <- this seems to start at zero and be 
going up at roughly 0x200 a second up to 0xFFFF then restarting at zero 
again over and over.

Just to give you a clearer picture, the bzImage is 1148021 bytes and 
doc_spl is 1187472 bytes. The nandwrite command wrote doc_spl from 0 up 
to the erase block at 0x118000 which is well within the 0x208000 
firmware area. The board is a Boser HS-4020 v1.4.

Unfortunately, assembler is greek to me!

- Zeri