Iliyan Malchev 2c1417b43a Serial: add input path overriding stdin for --serial ... Allowing the input to be specified for file-based serial ports allows the user of pipes as input/output. That enables kgdb over serial. TEST= Build a kernel with support for gdb ``` make x86_64_defconfig make kvmconfig ./scripts/config --enable GDB_SCRIPTS ./scripts/config --enable KGDB ./scripts/config --enable KGDB_SERIAL_CONSOLE ./scripts/config --enable KGDB_LOW_LEVEL_TRAP ./scripts/config --enable KGDB_KDB ./scripts/config --enable KDB_KEYBOARD ./scripts/config --enable GDB_SCRIPTS ./scripts/config --set-val KDB_CONTINUE_CATASTROPHIC 0 make -j33 ``` Setup devices for PTYs To make sure crosvm doesn't create an ordinary file if socat is started after it, create these named pipes first: ``` mkfifo ~/console_{in,out} ~/kgdb_{in,out} ``` Set up two PTYs: ~/kgdb for the debugger, and ~/serial for the console. PTY ~/kgdb connects to ~/kgdb{in,out}, and ~/serial connects to ~/console{in,out} ``` socat -d -d -d \ 'PIPE:$HOME/console_out,rdonly=1,nonblock=1,ignoreeof=1!!PIPE:$HOME/console_in,wronly=1' \ PTY,link=$HOME/serial,ctty,raw,echo=0 socat -d -d -d \ 'PIPE:$HOME/kgdb_out,rdonly=1,nonblock=1,ignoreeof=1!!PIPE:$HOME/kgdb_in,wronly=1' \ PTY,link=$HOME/kgdb,ctty,raw,echo=0 ``` Start crosvm with serial ports pointed at ~/console{in,out} and ~/kgdb{in,out}. ``` cargo run run -p 'init=/bin/sh panic=0 kgdboc=ttyS1,115200 kgdbwait kgdbcon' \ --serial type=file,path=$HOME/console_out,num=1,console=true,stdin=false,input=$HOME/console_in \ --serial type=file,path=$HOME/kgdb_out,input=$HOME/kgdb_in,num=2,console=false,stdin=false \ -r ~/rootfs.img \ ~/src/linux/arch/x86/boot/bzImage ``` Start GDB ``` gdb vmlinux -ex "target remote /home/dgreid/kgdb" ``` To break into gdb, open up the serial console, mount /proc and send a SysRq ``` minicom -D ~/serial mount -t proc none /proc echo g > /proc/sysrq-trigger ``` Change-Id: I18a9c1087d38301df49de08eeae2f8559b03463a Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2151856 Reviewed-by: Daniel Verkamp <dverkamp@chromium.org> Tested-by: Dylan Reid <dgreid@chromium.org> Commit-Queue: Dylan Reid <dgreid@chromium.org>		2020-04-19 22:22:46 +00:00
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src	Serial: add input path overriding stdin for --serial	2020-04-19 22:22:46 +00:00
Cargo.toml	audio: Create AC97 device with --ac97 option	2020-03-20 15:26:02 +00:00