I am compiling a hello world program in C on a 64-bit Linux machine. I am using a GCC ARM embedded toolchain to cross compile my program on a FOX G20 V board with an ATMEL AT91SAM9G20 processor.
On the first take, I had a few errors when compiling because the program didn't recognize the printf, return etc. functions (the standard C functions). So I decided to make the link between the functions, which I believe are defined in the libc.a library (correct me if I'm wrong), by doing
arm-none-eabi-gcc -o hello hello.c libc.a but the outcome still results in errors:
libc.a(lib_a-exit.o): In function `exit': exit.c:(.text.exit+0x16): undefined reference to `_exit' libc.a(lib_a-sbrkr.o): In function `_sbrk_r': sbrkr.c:(.text._sbrk_r+0xc): undefined reference to `_sbrk' libc.a(lib_a-writer.o): In function `_write_r': writer.c:(.text._write_r+0x10): undefined reference to `_write' libc.a(lib_a-closer.o): In function `_close_r': closer.c:(.text._close_r+0xc): undefined reference to `_close' libc.a(lib_a-fstatr.o): In function `_fstat_r': fstatr.c:(.text._fstat_r+0xe): undefined reference to `_fstat' libc.a(lib_a-isattyr.o): In function `_isatty_r': isattyr.c:(.text._isatty_r+0xc): undefined reference to `_isatty' libc.a(lib_a-lseekr.o): In function `_lseek_r': lseekr.c:(.text._lseek_r+0x10): undefined reference to `_lseek' libc.a(lib_a-readr.o): In function `_read_r': readr.c:(.text._read_r+0x10): undefined reference to `_read' collect2: error: ld returned 1 exit status
I'm really unsure as to why the program still does not recognize the standard functions even though I've linked the library to the application. If anyone has a reason as to why, or a solution as to how I can fix this problem, I would be very grateful.
I've downloaded the glibc library from here. I've compiled and created a static library from the
syscalls.c library that I found in
newlib-2.1.0/libgloss/arm and when I link the library to my application code, I still get the same error.