On Tue, 21 Feb 2023, 23:32 Josef Wolf, <jw@xxxxxxxxxxxxx> wrote: > Hello all, > > I am trying to build for a bare metal target without any OS support and I > want > to omit libc (newlib). > Do you mean you're trying to build GCC itself, or you're trying to build your own program? > So I add > > -ffunction-sections -nostdlib -ffreestanding > > flags to assembler/compiler and > > -lnosys -nolibc -nodefaultlibs -nostartfiles -nostdlib -ffreestanding > -static-libgcc -lgcc -lnosys -nolibc -nodefaultlibs -nostartfiles > -nostdlib -ffreestanding -static-libgcc -lgcc > > to linker Please show the full commands you're using If you add -v to the gcc command it will show exactly what it's doing. > > > But gcc still tries to pull newlib: > > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/bin/ld: > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libc.a(lib_a-init.o): > in function `__libc_init_array': > /var/tmp/builds/crossgcc/src/newlib-3.1.0/newlib/libc/misc/init.c:40: > undefined reference to `_init' > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/bin/ld: > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libc.a(lib_a-sbrkr.o): > in function `_sbrk_r': > /var/tmp/builds/crossgcc/src/newlib-3.1.0/newlib/libc/reent/sbrkr.c:51: > undefined reference to `_sbrk' > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/bin/ld: > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libc.a(lib_a-writer.o): > in function `_write_r': > /var/tmp/builds/crossgcc/src/newlib-3.1.0/newlib/libc/reent/writer.c:49: > undefined reference to `_write' > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/bin/ld: > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libc.a(lib_a-closer.o): > in function `_close_r': > /var/tmp/builds/crossgcc/src/newlib-3.1.0/newlib/libc/reent/closer.c:47: > undefined reference to `_close' > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/bin/ld: > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libc.a(lib_a-lseekr.o): > in function `_lseek_r': > /var/tmp/builds/crossgcc/src/newlib-3.1.0/newlib/libc/reent/lseekr.c:49: > undefined reference to `_lseek' > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/bin/ld: > /m/a/local/crossgcc/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/9.3.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libc.a(lib_a-readr.o): > in function `_read_r': > /var/tmp/builds/crossgcc/src/newlib-3.1.0/newlib/libc/reent/readr.c:49: > undefined reference to `_read' > collect2: error: ld returned 1 exit status > > So what is the magic option to tell gcc not to mess around with libc > (newlib)? > > Thanks! > > >
