C-Series/D-Series ARM core is Cortex-A8 (or perhaps Cortex-A9 in D-Series ?) == ARMv7 architecture. ARM7TDMI core was much older & simpler (ARMv4 architecture)..
Original Keil ULINK2 JTAG adapter supported ARM core list looks somehow limited to me (ARM7/ARM9/Cortex-M cores). Will it work with SDP1001 JTAG interface? I dunno.. maybe (at least on physical level).
Re: on-chip flash type: we don't even know if there is any on-chip flash in SDP1001 (ARM CPU may be starting from OneNAND boot block / 1kB BootRAM directly).
In general, OneNAND access (dumping/flashing) is tricky. Two methods I'm aware of:
1) Via JTAG boundary scan: really hard to figure out if there are no manufacturer specs available (SDP1001 is quite complex SoC, with great many pins/pads, and many internal CPU cores/subsystems). Doesn't look very promising - unless we can obtain detailed documentation somehow. Old-fashioned industrial espionage, perhaps
2) Use JTAG to load and run some specially crafted ARM code for re-flashing, using built-in chip controllers/external access capabilities. Those controllers are chip specific, too, but potentially much easier to figure out (we have U-Boot sources for B-Series, with OneNAND access code included, that should be a good start). Often, such code is already present in flash or BootROM, left out as backdoor/service/emergency access method. I remember there was one extra flash partition (at least in B/C-Series) with some OneNAND-related code on it; I wonder what is it exactly for?
For some devices, there are hidden/undocumented built-in auxiliary hardware interfaces for booting/flashing.. Interesting fact: all ARM-based B/C/D-Series mainboards I've seen so far have two test pads directly under OneNAND chips. I find that a little suspicious
I can't find any datasheet for KFG1GN6W2D used in D-series (?), and it doesn't follow Samsung own naming scheme; WTF is this kitty??
In B/C-Series they were using generic Samsung-made flex-OneNANDs (SLC + MLC), with detailed specs/datasheets easily available. No built-in 2-wire interface of any kind mentioned in the datasheets, though. So, what are those two pads used for?