The globals
end , etext
and
edata
are program segment end addresses.
etext
is the first address after the end of the text segment.
edata
is the first address after the end of the initialized data segment.
end
is the first address after the end of the data segment
(BSS
)
when the program is loaded.
Use the
sbrk(2)
system call with zero as its argument to find the current end of the
data segment.
Traditionally, no variable existed that pointed to the start of the
text segment because the text segment always started at address zero.
Although it is no longer valid to make this assumption, no
variable similar to the ones documented above exists to point to the
start of the text segment.