WhyCan Forum(哇酷开发者社区)

buildroot使用外部编译工具链，会导致panic，使用内部工具链，则可以正常启动。

Toolchain设置
1. Toolchain type (External toolchain)  --->
2. Toolchain (Custom toolchain)
3. Toolchain origin (Pre-installed toolchain)
4. (/opt/gcc-linaro-7.2.1-2017.11-x86_64_arm-linux-gnueabi) Toolchain
5. (arm-linux-gnueabi) Toolchain prefix
6. External toolchain gcc version (7.x)  --->
7. External toolchain kernel headers series (4.10.x)
8. External toolchain C library (glibc/eglibc)
9. [//*] Toolchain has SSP support? (NEW)
10.[//*] Toolchain has RPC support? (NEW)

问题：
1. 按照上面设置编译出来，运行会导致panic，如下，什么原因
[    1.786977] VFS: Mounted root (jffs2 filesystem) on device 31:3.
[    1.795787] devtmpfs: mounted
[    1.805273] Freeing unused kernel memory: 1024K
[    2.074266] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[    2.074266]
[    2.083419] CPU: 0 PID: 1 Comm: init Not tainted 4.15.0-rc8-licheepi-nano+ #5
[    2.090537] Hardware name: Allwinner suniv Family
[    2.095323] [<c010e550>] (unwind_backtrace) from [<c010b6a8>] (show_stack+0x10/0x14)
[    2.103079] [<c010b6a8>] (show_stack) from [<c0116878>] (panic+0xb8/0x230)
[    2.109958] [<c0116878>] (panic) from [<c0118034>] (do_exit+0x96c/0x9a4)
[    2.116659] [<c0118034>] (do_exit) from [<c0118bb8>] (do_group_exit+0x3c/0xb4)
[    2.123877] [<c0118bb8>] (do_group_exit) from [<c0121758>] (get_signal+0x144/0x558)
[    2.131537] [<c0121758>] (get_signal) from [<c010a934>] (do_signal+0xc4/0x404)
[    2.138766] [<c010a934>] (do_signal) from [<c010ae3c>] (do_work_pending+0xb8/0xcc)
[    2.146335] [<c010ae3c>] (do_work_pending) from [<c0107d48>] (slow_work_pending+0xc/0x20)
[    2.154500] Rebooting in 5 seconds..
[    8.133732] Reboot failed -- System halted

2. 使用外部工具链时，设置8. External toolchain C library (glibc/eglibc)必须选择glibc/eglibc ，不然编译会报错c lib选择错误，这是为何
3. 使用外部工具链时，设置7. External toolchain kernel headers series (4.10.x) 必须选择4.10.x ， 我选4.15.x会报错显示预期是4.15，实际是4.10，
    这个4.10.x是由哪里决定的？

4. 如果使用内部工具链，则设置8中的C library 随便选哪个都可以编译通过，而且系统可以正常运行，原因何在