I used SDCC complier
i had a problem with my test.c
#include "8051.h"
main()
(P1=0;
P2=0;
}
i complie test.c with command line
below
sdcc --model-small --code-loc 0x8000
and i also recived no errors
and load file test.hex to my board(use
monitor program,my external ram begin at 8000h)
it run properly.
However
i complied this test.c by command line:
sdcc --model-small --code-loc 0x0000
and received no errors
but when i load test.hex to another board (not use
monitor program)
It didn't run properly(P1 and p2 always are
high)

I dont know why
I want to fix this problem as soon as possible ,it made me stuck for a month.
can you help me?