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linuxoperating-systemgnu-efi

qemu hangs after booting a GNU-EFI os

I was trying to write a "hello world" x86_64 OS with GNU-EFI according to an article:https://wiki.osdev.org/GNU-EFI, but I ran into some problem.

When I boot the img using following command

sudo qemu-system-x86_64 -drive file=$(BUILD_DIR)/$(OSNAME).img -m 256M -cpu qemu64 \
    -drive if=pflash,format=raw,unit=0,file="$(OVMF_DIR)/OVMF_CODE.fd",readonly=on \
    -drive if=pflash,format=raw,unit=1,file="$(OVMF_DIR)/OVMF_VARS.fd" \
    -net none

Qemu hangs after printing Found bootloader on fs0:

I can't find out what cause it. I suspect I made some mistakes in the Makefile. Heres the code repo:https://github.com/xubury/myos for reproduce.

BTW, you may need to specify path to gnu-efi and ovmf in the Makefile.

I ran the code under OS: Arch Linux x86_64 and Kernel: 5.11.1-arch1-1

Many thanks in advance!

Solution

  • So, apparently the problem goes away when I put -lgnuefi -lefi at the end of the linkage. But I don't know excatly why. Also, the gnu-efi function should be called using uefi_call_warpper for some ABI compatibility issues.