Looks like there are some fiddly bits about configuring the kernel. Practically speaking, configuration needs to first be done within the VM, then everything can be moved and compiled outside of it. How do I submit a final writeup to put somewhere? On Thu, Apr 18, 2024 at 3:27 PM Josh Marshall <joshua.r.marshall.1991@xxxxxxxxx> wrote: > > There's a type already. Term 1 should be: > > qemu-system-x86_64 -s -cpu host -nographic -accel kvm -m 1G -kernel > arch/x86/boot/bzImage -append "root=/dev/sdb3 rw > console=ttyS0,115200n8" -drive > format=qcow2,file=$HOME/Downloads/Arch-Linux-x86_64-basic.qcow2 > > However, the kernel panics because it can't mount the root FS on an > unknown block. I don't know what the cause is. However, the UUIDs > are scrambled from what are in GRUB. Is there some sort of security > going on here? > > On Thu, Apr 18, 2024 at 3:15 PM Josh Marshall > <joshua.r.marshall.1991@xxxxxxxxx> wrote: > > > > So the final outline would look like the following? > > > > Source: > > https://github.com/archlinux/arch-boxes > > > > setup: > > > > git clone $LINUX_REPO & > > wget https://geo.mirror.pkgbuild.com/images/latest/Arch-Linux-x86_64-basic.qcow2 > > > > echo add-auto-load-safe-path > > “$LINUX_REPO_PATH/scripts/gdb/vmlinux-gdb.py” >> > > "$HOME/.config/gdb/gdbinit" > > > > echo ‘export LIBGUESTFS_DEBUG=1 LIBGUESTFS_TRACE=1’ >> $HOME/.bashrc > > echo ‘export USERCFLAGS=" -ggdb "’ >> $HOME/.bashrc > > > > push $LINUX_REPO_PATH > > > > echo “CONFIG_SATA_AHCI=y” >> .config > > echo “CONFIG_DEBUG_INFO=y” >> .config > > echo “CONFIG_DEBUG_INFO_DWARF5=y” >> .config > > echo “CONFIG_GDB_SCRIPTS=y” >> .config > > echo “CONFIG_GDB_INFO_REDUCED=n” >> .config > > echo “CONFIG_KGDB=y” >> .config > > echo “CONFIG_FRAME_POINTER=y” >> .config > > echo “CONFIG_KVM_GUEST=y” >> .config > > echo “CONFIG_RANDOMIZE_BASE=n” >> .config > > > > make localyesconfig > > pop > > > > source $HOME/.bashrc > > mkdir -p $HOME/mnt/arch > > > > Iterate: > > guestmount -w -a $HOME/Downloads/Arch-Linux-x86_64-basic.qcow2 -m > > /dev/sda3 ~/mnt/arch/ > > <copy sources, files, perform compilation steps, etc as needed to > > inside the VM image as needed each development iteration> > > umount ~/mnt/arch > > > > Term 1: > > qemu-system-x86_64 -s -cpu host -nographic -accel kvm -m 1G -kernel > > vmlinux2 -append "root=/dev/sda3 rw console=ttyS0,115200n8 nokaslr > > " -drive format=qcow2,file=$HOME/Downloads/Arch-Linux-x86_64-basic.qcow2 > > > > Term 2: > > gdb $LINUX_REPO_PATH/vmlinux > > : target remote:1234 > > <set break points> > > : continue > > > > On Thu, Apr 18, 2024 at 11:36 AM ngn <ngn@xxxxxx> wrote: > > > > > > On Wed, Apr 17, 2024 at 05:18:34PM -0400, Josh Marshall wrote: > > > > One issue I'm seeing is that gdb isn't seeing debugging symbols. I'm > > > > getting the following output with the config linked. > > > > > > > > https://pastebin.com/tjq7QtQk > > > > > > > > ``` > > > > anadon@botamon:~/Documents/code/linux$ gdb arch/x86/boot/bzImage > > > > GNU gdb (Ubuntu 15.0.50.20240403-0ubuntu1) 15.0.50.20240403-git > > > > Copyright (C) 2024 Free Software Foundation, Inc. > > > > License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> > > > > This is free software: you are free to change and redistribute it. > > > > There is NO WARRANTY, to the extent permitted by law. > > > > Type "show copying" and "show warranty" for details. > > > > This GDB was configured as "x86_64-linux-gnu". > > > > Type "show configuration" for configuration details. > > > > For bug reporting instructions, please see: > > > > <https://www.gnu.org/software/gdb/bugs/>. > > > > Find the GDB manual and other documentation resources online at: > > > > <http://www.gnu.org/software/gdb/documentation/>. > > > > > > > > For help, type "help". > > > > Type "apropos word" to search for commands related to "word"... > > > > Reading symbols from arch/x86/boot/bzImage... > > > > (No debugging symbols found in arch/x86/boot/bzImage) > > > > ``` > > > > > > > > > > You should load vmlinux to the gdb, not the bzImage. bzImage is a > > > compressed version of the kernel and its used boot, vmlinux is the > > > static ELF binary that contains the debugging symbols.
