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| -rw-r--r-- | Hurd/DebuggingViaSubhurds.mdwn | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/Hurd/DebuggingViaSubhurds.mdwn b/Hurd/DebuggingViaSubhurds.mdwn new file mode 100644 index 00000000..20855da6 --- /dev/null +++ b/Hurd/DebuggingViaSubhurds.mdwn @@ -0,0 +1,85 @@ +## <a name="General_Information"> General Information </a> + +See the [[SubhurdHowto]] for general information about subhurds. + +---- + +## <a name="Debugging_the_Hurd_Startup_Proce"> Debugging the Hurd Startup Process </a> + +_one.full_ is the subhurd's root file system image and has been installed as follows: [TODO] + +_Wx_ translates to terminal window _x_. + +W1 + + $ fsysopts one.full/ --readonly + $ sudo boot -I -d -s -D one.full/ one.full/boot/script.boot one.full.ext2 + Pausing. . . + +(In theory it shouldn't be neccessary to run the subhurd as user _root_, but in practice [that doesn't work at the moment](http://savannah.gnu.org/bugs/?17341).) + +W2 + + $ ps -Af + [...] + root 851 385 p4 0:00.01 boot -I -d -s -D one.full/ one.full/boot/script.boot one.full.ext2 + - 853 1 ? 0:00.00 ? + - 854 1 ? 0:00.00 ? + [...] + $ sudo gdb /var/tmp/one.full/hurd/ext2fs.static + [...] + (gdb) attach 853 + Attaching to program `/var/tmp/one.full/hurd/ext2fs.static', pid 853 + warning: Can't modify tracing state for pid 853: No signal thread + Can't fetch registers from thread 1: No such thread + +(The _boot_ program [could be modified to print out the pids](http://savannah.gnu.org/bugs/?19254), so that one wouldn't have to fumble with _ps_.) + +W3 + + $ sudo gdb /var/tmp/one.full/hurd/exec + [...] + (gdb) set solib-absolute-prefix /var/tmp/one.full + (gdb) attach 854 + Attaching to program `/var/tmp/one.full/hurd/exec', pid 854 + warning: Can't modify tracing state for pid 854: No signal thread + Can't fetch registers from thread 1: No such thread + +W1 + + [<Enter>.] + /hurd/ext2fs.static --bootflags=-dsf --host-priv-port=38 --device-master-port=43 --exec-server-task=47 -Tdevice pseudo-root + /lib/ld.so.1 /hurd/exec + +W2 + + (gdb) continue + Continuing. + warning: Can't wait for pid 853: No child processes + +W1 + + Hurd server bootstrap: ext2fs.static[pseudo-root] exec + +W3 + + (gdb) continue + Continuing. + warning: Can't wait for pid 854: No child processes + + Program received signal EXC_BAD_ACCESS, Could not access memory. + 0x000168f2 in ?? () + (gdb) bt + #0 0x000168f2 in ?? () + Cannot access memory at address 0xbeffffe4 + (gdb) info threads + * 1 thread 1005.1 0x000168f2 in ?? () + (gdb) disassemble + No function contains program counter for selected frame. + +---- + +Sources: + +* <http://www.gnu.org/software/hurd/howto/subhurd.html> +* <http://lists.gnu.org/archive/html/bug-hurd/2007-02/msg00030.html> |