编译时加了-g选项但还是有no symbol ...no line information

请问老大,编译时我加了-g选项,还是有
load
Loading section first, size 0x8f4 lma 0x0
Loading section second, size 0x2fc lma 0x8fc
Start address 0x0, load size 3056
Transfer rate: 38 KB/sec, 1528 bytes/write.
break _start
Breakpoint 1 at 0x0
continue
Breakpoint 1, 0x00000000 in _start ()
Single stepping until exit from function _start,
which has no line number information.
No symbol table is loaded.  Use the "file" command.
No symbol table is loaded.  Use the "file" command.

makefile与lds文件都在截图里了,,,这是视频的mmu实验