end, etext, edata on ATT 3B2

[Bill Dietrich]

The MMU used by the 3B-2/300 splits the 32-bit virtual
address space and its own internal caches into
4 "sections" via the top two bits of the 32-bit
address.  So to distribute accesses somewhat uniformly
through the MMU caches, 3B-2 Unix puts some kernel
stuff in section 0 (virtual addresses 0x00000000 - 0x3FFFFFFF),
kernel text and data in section 1 (0x40000000 - 0x7FFFFFFF),
user text and data in section 2 (0x80000000 - 0xBFFFFFFF),
and user stack in section 3 (0xC0000000 - 0xFFFFFFFF).

So even for a small program, you will see what
looks like "big" addresses.  You can see concrete numbers
by using the "dump -h" command on "/unix" and your
program.  This command prints the section header information
from an object file.  Or use "nm" on those files.


				Bill Dietrich
				AT&T Information Systems
				houxj!wapd