Linker 错误：未定义对 _fbss 的引用

Question

I'm sucessfully building pulp-riscv-gnu-toolchain from this this

But when I try to compile my simple source code with builded compiler, error occured.

My command is riscv32-unknown-elf-g++ -o hello hello.cpp

Error message is /home/jskim/test_toolchains_lib/gcc/riscv32-unknown-elf/7.1.1/../../../../riscv32-unknown-elf/bin/ld: cannot open linker script file riscv.ld: No such file or directory

So I try with this command riscv32-unknown-elf-g++ -o main main.cpp -T /home/jskim/test_toolchains/riscv32-unknown-elf-ld/lib/ldscripts/elf32lriscv.x

But following error occured: /home/jskim/test_toolchains/lib/gcc/riscv32-unknown-elf/7.1.1/../../../../riscv32-unknown-elf/lib/crt0.o: In function '.L0': (.text+0x10):undefined reference to '_fbss' collect2: error: ld returned 1 exit status

I'm using CentOS 7.6 and I try build this pulp-gcc with gcc 4.8.5 and 7.3.1 but both shows me same error. Please help me.

Answer 1

I resolve the problem in this way.

Actually Here is the solution.

I'm not accurate but I think the problem is that the name is not matched. crt0, which seems to be the helper of start riscv processor has this line la a0 _fbss just basically linker can recognize this if _fbss is replaced with _edata. So i edit the assembly file which is located at pulp-riscv-gnu-toolchain/riscv-newlib/libgloss/riscv/ And rebuild the gnu toolchain. And execute your compiler with -T option like riscv32-unknown-elf-g++ -o main main.cpp -T /home/jskim/test_toolchains/riscv32-unknown-elf-ld/lib/ldscripts/elf32lriscv.x

This is the easiest solution as I think.