| A simple x86 firmware that can boot Linux. |
| |
| Most of QEMU's startup time is spent: |
| |
| * in the dynamic linker. This can be reduced by 150 ms simply by |
| compiling a stripped down QEMU: |
| |
| ./configure --disable-libssh2 --disable-tcmalloc --disable-glusterfs \ |
| --disable-seccomp --disable-{bzip2,snappy,lzo} --disable-usb-redir \ |
| --disable-libusb --disable-smartcard-nss --disable-libnfs \ |
| --disable-libiscsi --disable-rbd --disable-spice --disable-attr \ |
| --disable-cap-ng --disable-linux-aio --disable-brlapi \ |
| --disable-vnc-{jpeg,tls,sasl,png,ws} --disable-rdma --disable-bluez \ |
| --disable-fdt --disable-curl --disable-curses --disable-sdl \ |
| --disable-gtk --disable-tpm --disable-vte --disable-vnc \ |
| --disable-xen --disable-opengl --target-list=x86_64-softmmu |
| |
| * in the BIOS. qboot saves another 150 ms. |
| |
| * until QEMU 2.7+, in fw_cfg. qboot uses the DMA interface which is pretty |
| much instantaneous. |
| |
| Compile qboot |
| ============= |
| |
| Clone the source: |
| |
| $ git clone https://github.com/bonzini/qboot.git |
| |
| Compile the qboot firmware (you may need to install the relevant build |
| time dependancies): |
| |
| $ meson build && ninja -C build |
| |
| The result will be a 64K file named bios.bin under the build/ directory. |
| |
| Usage |
| ===== |
| |
| $ qemu-kvm -bios bios.bin \ |
| -kernel /boot/vmlinuz-4.0.3-300.fc22.x86_64 \ |
| -serial mon:stdio -append 'console=ttyS0,115200,8n1' |
| |
| TODO |
| ==== |
| |
| * Add the possibility to configure out PIC and PCI bridge initialization |
