With an algorithm, explain pass1 of a linking loader
Pass 1:
Begin
get PROOADDR from operating system
set CSADDR to PROOADDR {for first control section}
while not end of input do
begin
read next input record {Header record for control section}
set CSLTH to control section length
search ESTAB for control section name
if found then
set error flag {duplicate external symbol}
else
enter control section name into ESTAB with value CSADDR
while record type ~ 'E' do
begin
read next input record
if record type = 'D' then
for each symbol in the record do
begin
search ESTAB for symbol name
if found then
set error flag (duplicate external symbol)
else
enter symbol into ESTAB with value(CSADDR + indicated address)
end {for}
end {while ~ 'E'}
add CSLTH to CSADDR {starting address for next control section}
end {while not EOF}
end {Pass 1}