如何从c代码和汇编代码RISCV生成十六进制文件

Question

我有一些C代码/汇编代码，我想编译它并为RISCV pulppissimo生成十六进制文件。有没有人能帮我完成这些步骤。当前正在运行hello代码

#include <stdio.h>

int main()
{
  printf("Hello !\n");

  return 0;
}

在使用riscv32进行编译时，使用命令riscv32-unknown-elf-gcc hello.c

遇到这样的错误

RISCV/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
collect2: error: ld returned 1 exit status

Answer 1

git 存储库中有一个完美的示例boot code，可用于回答您的问题。由于我没有您正在使用的工具链，因此我使用的是从 bootlin 网站下载的工具链。

wget https://toolchains.bootlin.com/downloads/releases/toolchains/riscv32-ilp32d/tarballs/riscv32-ilp32d--glibc--bleeding-edge-2020.02-2.tar.bz2
mkdir -p /opt/bootlin
tar jxvf riscv32-ilp32d--glibc--bleeding-edge-2020.02-2.tar.bz2 -C /opt/bootlin

git clone git clone https://github.com/pulp-platform/boot-code
cd boot-code

编辑Makefile，并调整以下行，以反映正在使用的工具链的位置：

PULP_CC = riscv32-unknown-elf-gcc
PULP_LD = riscv32-unknown-elf-gcc

当使用bootlin工具链时，这将导致以下两行：

PULP_CC = /opt/bootlin/riscv32-ilp32d--glibc--bleeding-edge-2020.02-2/bin/riscv32-buildroot-linux-gnu-gcc
PULP_LD = /opt/bootlin/riscv32-ilp32d--glibc--bleeding-edge-2020.02-2/bin/riscv32-buildroot-linux-gnu-gcc

同样的Makefile，替换下面这一行--代码不能像我想的那样编译：

CFLAGS += -Os -g -fno-jump-tables -I$(CURDIR)/include 

出自：

CFLAGS += -Os -g -fno-jump-tables -I$(CURDIR)/include -DMCHAN_CMD_ILE_BIT=21 -DMCHAN_CMD_ELE_BIT=20

现在可以构建build/bootcode可执行文件：

make
CC  boot_code.c
In file included from /home/frant/mnt/git/boot-code/include/hal/chips/pulp/pulp.h:20,
                 from /home/frant/mnt/git/boot-code/include/hal/pulp.h:27,
                 from boot_code.c:18:
/home/frant/mnt/git/boot-code/include/hal/riscv/riscv_v5.h: In function ‘hal_cluster_id’:
/home/frant/mnt/git/boot-code/include/hal/riscv/riscv_v5.h:172:10: warning: implicit declaration of function ‘__builtin_pulp_ClusterId’ [-Wimplicit-function-declaration]
  172 |   return __builtin_pulp_ClusterId();
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/frant/mnt/git/boot-code/include/hal/chips/pulp/pulp.h:21,
                 from /home/frant/mnt/git/boot-code/include/hal/pulp.h:27,
                 from boot_code.c:18:
/home/frant/mnt/git/boot-code/include/hal/eu/eu_v3.h: In function ‘evt_read32’:
/home/frant/mnt/git/boot-code/include/hal/eu/eu_v3.h:43:11: warning: implicit declaration of function ‘__builtin_pulp_event_unit_read’ [-Wimplicit-function-declaration]
   43 |   value = __builtin_pulp_event_unit_read((int *)base, offset);
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CC  crt0.S
LD  /home/frant/mnt/git/boot-code/build/bootcode
./stim_utils.py  \
        --binary=/home/frant/mnt/git/boot-code/build/bootcode \
        --stim-bin=rom.bin \
        --area=0x1a000000:0x01000000
Created stimuli generator
  Added binary: /home/frant/mnt/git/boot-code/build/bootcode
  Added target area: [0x1a000000 -> 0x1b000000]
  Handling section (base: 0x1a000000, size: 0x57c)
  Bypassing section (base:make
CC  boot_code.c
In file included from /home/frant/mnt/git/boot-code/include/hal/chips/pulp/pulp.h:20,
                 from /home/frant/mnt/git/boot-code/include/hal/pulp.h:27,
                 from boot_code.c:18:
/home/frant/mnt/git/boot-code/include/hal/riscv/riscv_v5.h: In function ‘hal_cluster_id’:
/home/frant/mnt/git/boot-code/include/hal/riscv/riscv_v5.h:172:10: warning: implicit declaration of function ‘__builtin_pulp_ClusterId’ [-Wimplicit-function-declaration]
  172 |   return __builtin_pulp_ClusterId();
      |          ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/frant/mnt/git/boot-code/include/hal/chips/pulp/pulp.h:21,
                 from /home/frant/mnt/git/boot-code/include/hal/pulp.h:27,
                 from boot_code.c:18:
/home/frant/mnt/git/boot-code/include/hal/eu/eu_v3.h: In function ‘evt_read32’:
/home/frant/mnt/git/boot-code/include/hal/eu/eu_v3.h:43:11: warning: implicit declaration of function ‘__builtin_pulp_event_unit_read’ [-Wimplicit-function-declaration]
   43 |   value = __builtin_pulp_event_unit_read((int *)base, offset);
      |           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CC  crt0.S
LD  /home/frant/mnt/git/boot-code/build/bootcode
./stim_utils.py  \
        --binary=/home/frant/mnt/git/boot-code/build/bootcode \
        --stim-bin=rom.bin \
        --area=0x1a000000:0x01000000
Created stimuli generator
  Added binary: /home/frant/mnt/git/boot-code/build/bootcode
  Added target area: [0x1a000000 -> 0x1b000000]
  Handling section (base: 0x1a000000, size: 0x57c)
  Bypassing section (base: 0x1c000000, size: 0x1928)
objcopy --srec-len 1 --output-target=srec /home/frant/mnt/git/boot-code/build/bootcode /home/frant/mnt/git/boot-code/build/bootcode.s19
./s19toboot.py /home/frant/mnt/git/boot-code/build/bootcode.s19 boot_code.cde pulp 0x1c000000, size: 0x1928)
objcopy --srec-len 1 --output-target=srec /home/frant/mnt/git/boot-code/build/bootcode /home/frant/mnt/git/boot-code/build/bootcode.s19
./s19toboot.py /home/frant/mnt/git/boot-code/build/bootcode.s19 boot_code.cde pulp

并将其转换为Intel十六进制格式：

/opt/bootlin/riscv32-ilp32d--glibc--bleeding-edge-2020.02-2/bin/riscv32-buildroot-linux-gnu-objcopy  --output-target=ihex build/bootcode bootcode.ihex

cat bootcode.ihex
:020000041A00E0
:100000006F0080086F0040086F0000086F00C00795
:100010006F0080076F0040076F0000076F00C00689
../...
:081920000000000000000000BF
:040000051A000000DD
:00000001FF

现在你已经有了一个我认为是你的目标的纸浆平台的工作示例，你应该能够根据你的需求来调整它。