From a5300c4949b8d4de2d34bedfaed66793f48ec948 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Fri, 22 May 2020 09:36:52 +0200 Subject: qboot: Disable PIE for ELF binary build step The switch to meson in commit fd2aada36b98 ("Add meson build") had two major behavior changes for the ELF binary build step: * ELF binary is no longer build as x86_64 on x86_64 * ELF binary is build as position independent executable on systems with a "--enable-default-pie" gcc The latter will create a slightly larger than 64KB bios.bin which causes an error when Qemu tries to load it: qemu: could not load PC BIOS 'qboot/build/bios.bin' This behavior change was introduced because the elf linker step was changed from using ld directly to using cc. Basically something like following Makefile change: bios.bin.elf: $(obj-y) flat.lds - $(LD) -T flat.lds -o bios.bin.elf $(obj-y) + $(CC) -o bios.bin.elf $(obj-y) -Wl,--no-undefined -Wl,--as-needed -nostdlib -m32 -Wl,--build-id=none -Wl,-Tflat.lds GCC will then take care of calling ld with the appropriate arguments. And one of these arguments for the "--enable-default-pie" gcc is "-pie": $(LD) --build-id --eh-frame-hdr -m elf_i386 --hash-style=gnu -dynamic-linker /lib/ld-linux.so.2 -pie -o bios.bin.elf $(obj-y) --no-undefined --as-needed --build-id=none -Tflat.lds This default behavior of gcc must be suppressed by adding -no-pie to the arguments when linking the object files. Signed-off-by: Sven Eckelmann --- meson.build | 1 + 1 file changed, 1 insertion(+) diff --git a/meson.build b/meson.build index 2aef8c9..d060f75 100644 --- a/meson.build +++ b/meson.build @@ -18,6 +18,7 @@ c_args = [ link_args = ['-nostdlib', '-m32'] link_args += cc.get_supported_link_arguments('-Wl,--build-id=none') link_args += '-Wl,-T' + meson.current_source_dir() / 'flat.lds' +link_args += cc.get_supported_link_arguments(['-no-pie']) elf = executable( 'bios.bin.elf', -- cgit v1.1