Hello,
Am 18.10.2021 um 22:29 schrieb Glenn Washburn:
I can't say I'm a fan of another special variable, but I'd also be fine with that route. Another route might be a (proc) file, eg. "/gsyms", which outputs add-symbol-file lines for all loaded modules. This could be put in its own module, eg. gdb-syms, which would address the increasing the core image size concern below.
To be honest I was not even aware that (proc) was a thing in Grub. In fact, procfs is not loaded in any grub I have here, and loading it does not make any files appear in it either (if I can trust the ls command).
If I understand this correctly, you're thinking I'm talking about *appending* a new line to the debug message. I'm talking about *prepending*. So we're on the same page, the entire message is formatted currently as "file:line:<debug message>". I'm not sure I understand the last sentence, the debug message as proposed in the patch is already a multi-line message.
Ok, then rather "every fourth line" instead of "every second line"? I have to admit I did not actually apply and test the patch. From the patch content, when not using qdprintf, it looked to me that the output would be similar to kern/efi/init.c:2222 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/kernel.exec \\ 40005678 -s .data 40009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/efidisk.debug \\ 10005678 -s .data 10009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/ext2.debug \\ 20005678 -s .data 20009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/gfxterm.debug \\ 30005678 -s .data 30009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/normal.debug \\ 30005678 -s .data 30009876 And with prepending a newline, it would look like this: kern/efi/init.c.c:2222 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/kernel.exec \\ 40005678 -s .data 40009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/efidisk.debug \\ 10005678 -s .data 10009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/ext2.debug \\ 20005678 -s .data 20009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/gfxterm.debug \\ 30005678 -s .data 30009876 kern/dl.c:1111 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/normal.debug \\ 30005678 -s .data 30009876 And what you need to copy into gdb would be add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/kernel.exec \\ 40005678 -s .data 40009876 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/efidisk.debug \\ 10005678 -s .data 10009876 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/ext2.debug \\ 20005678 -s .data 20009876 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/gfxterm.debug \\ 30005678 -s .data 30009876 add-symbol-file \\ /usr/lib/debug/usr/lib/grub/x86_64-efi/normal.debug \\ 30005678 -s .data 30009876 If that assumption is wrong, I am sorry for misinterpreting the patch and stealing your time.
Interesting idea. Also, I had thought of having an in memory ring-buffer for playing back debug log on a live grub.
The interesting question is how to play it back as in my experience, GRUB usually locks up when I need this. So there is no real way to return to the shell so you could play it back again. (On the other hand, this would require to synchronously write the logs to disk and not buffer them, or you would miss the last few). But probably there are other cases where you actually could return to the prompt. Regards, Michael _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
