diff --git a/ppt/qemu-boot-hang-debug-upstream-practice.pdf b/ppt/qemu-boot-hang-debug-upstream-practice.pdf new file mode 100644 index 0000000000000000000000000000000000000000..9fd4c8eabef2c628b72c5e3df715a53faf59e2f3 Binary files /dev/null and b/ppt/qemu-boot-hang-debug-upstream-practice.pdf differ