使用 gdb 调试 xv6 代码无法读取符号表

Question

我在使用 qemu-gdb 时遇到问题。我在一个选项卡中执行了

make qemu-gdb

，在另一个选项卡中执行了

riscv64-unknown-elf-gdb

。然后我得到这个：

riscv64-unknown-elf-gdb kernel/kernel
GNU gdb (GDB) 10.1
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
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There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "--host=x86_64-apple-darwin21.5.0 --target=riscv64-unknown-elf".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
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    <http://www.gnu.org/software/gdb/documentation/>.

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/Users/lichenglong/.gdbinit:1: Error in sourced command file:
No symbol table is loaded.  Use the "file" command.
Reading symbols from kernel/kernel...
warning: File "/Users/username/cs_study/os/6S081/labs/xv6-labs-2022/.gdbinit" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
To enable execution of this file add
    add-auto-load-safe-path /Users/username/cs_study/os/6S081/labs/xv6-labs-2022/.gdbinit
line to your configuration file "/Users/username/.gdbinit".
To completely disable this security protection add
    set auto-load safe-path /
line to your configuration file "/Users/username/.gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
    info "(gdb)Auto-loading safe path

根据提示，我在文件

add-auto-load-safe-path /Users/username/cs_study/os/6S081/labs/xv6-labs-2022/.gdbinit

中添加

/Users/username/.gdbinit

行。当我执行

source /Users/username/.gdbinit

时，提示

command not found: add-auto-load-safe-path

。 然后我将

set auto-load safe-path /

行添加到文件并获取它。但是当我运行

riscv64-unknown-elf-gdb

.

时，我得到了相同的结果