Here is a little background:
Going by this
Guide (where I got most info from) the compressed image of Androids root file system is part of a boot image residing on a partition.
The T1 however seems to follow a different approach with a stand-alone root fs image in form of raw data on the unpartitioned area.
Code:
cat /sys/module/rawdatatable/parameters/rawdata_param
MBR :0x00000000:0x00000400
uBoot :0x00000400:0x000bfc00
Boot Env :0x000c0000:0x00020000
Reserved1 :0x000e0000:0x00020000
Normal Kernel :0x00100000:0x00400000
Normal Rootfs :0x00500000:0x00100000
Recovery Kernel :0x00600000:0x00400000
Reserved2 :0x00a00000:0x00500000
Normal Boot Env :0x00f00000:0x00020000
Recovery Boot Env :0x00f20000:0x00020000
Raw Data Table :0x00f40000:0x00020000
Info :0x00f60000:0x00020000
Id :0x00f80000:0x00020000
Reserved3 :0x00fa0000:0x00060000
Boot Image :0x01000000:0x00100000
Waveform :0x01100000:0x00200000
LOG :0x01300000:0x00500000