The gdt address calculation in linuxboot.bin is broken in two ways: first
it loads %cs into %eax, but that instruction leaves the high bits of %eax
undefined and we did not clear them. Secondly, we completely ignore the
incorrect %eax, and use the undefined %ebx instead.
With these issues fixed, linuxboot works again.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The vpath directive has two advantages over the VPATH variable:
1) it allows to skip searching of .o files; 2) the default semantics
are to append to the vpath, so there is no confusion between "VPATH=xyz"
and "VPATH+=xyz".
Since "vpath %.c %.h PATH" is not valid, I'm introducing a wrapper
macro to append one or more directories to the vpath.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The %gs segment that was used was not matching the comments.
I just moved the GDT descriptor on the stack instead.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
While trying to run -kernel with -bios pc-bios/pcbios.bin, I realized
that I was actually writing data to %es, but only set up %ds to a 32-bit
segment we want to write to.
So at the end of the day the data hasn't actually been copied. Oops.
So here's a fix to set ES instead of DS, which makes -kernel work with
BOCHS bios again (and actually makes the code do the correct thing)!
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In the spirit of ff56954baf, fix the
build of linuxboot.S with old as(1) (as found in some BSD base systems)
by emitting the bytes of the insn it doesn't like instead.
Signed-off-by: Juergen Lock <nox@jelal.kn-bremen.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
We already have a working multiboot implementation that uses fw_cfg to get
its kernel module etc. data in int19 runtime now.
So what's missing is a working linux boot option rom. While at it I figured it
would be a good idea to take the opcode generator out of pc.c and instead use
a proper option rom, like we do with multiboot.
So here it is - an fw_cfg using option rom for -kernel with linux!
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We will have a linux boot option rom soon, so let's take all functionality
that might be useful for both to a header file that both roms can include.
That way we only have to write fw_cfg access code once.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Right now we load the guest kernel to RAM, fire off the BIOS, hope it
doesn't clobber memory and run an option rom that jumps into the kernel.
That breaks with SeaBIOS, as that clears memory. So let's read all
kernel, module etc. data using the fw_cfg interface when in the int19
handler.
This patch implements said mechanism for multiboot.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
On Wed, Sep 23, 2009 at 10:55:02PM +0200, Juergen Lock wrote:
> On Wed, Sep 23, 2009 at 09:31:16PM +0100, Laurence Tratt wrote:
>[...]
> > then the above error doesn't occur, but
> > pc-bios/optionrom/multiboot.S dies as follows:
> >
> > $
> > AS optionrom/multiboot.o
> > multiboot.S: Assembler messages:
> > multiboot.S:116: Error: `%es:-4(%edi)' is not a valid 16 bit base/index
> > expression
> > $
> >
> > What little Intel assembler I ever knew has long since departed from my
> > brain, so I don't know why that error occurs, nor what a fix might be.
> >
> It occurs because of too old binutils (as(1) in this case), on FreeBSD
> we now have a port for newer ones,
> http://www.freshports.org/devel/binutils
> so I depend on that and have the optionrom Makefile use the new as
> like this: (the first change wrt CFLAGS is unrelated and has probably
> been fixed in the meantime; it caused gmake to complain about
> recursive use of CFLAGS.)
>
> Index: qemu/pc-bios/optionrom/Makefile
> @@ -9,10 +9,13 @@
>
> CFLAGS = -Wall -Wstrict-prototypes -Werror -fomit-frame-pointer -fno-builtin
> CFLAGS += -I$(SRC_PATH)
> -CFLAGS += $(call cc-option, $(CFLAGS), -fno-stack-protector,"")
> +CFLAGS := $(CFLAGS) $(call cc-option, $(CFLAGS), -fno-stack-protector,"")
>
> build-all: multiboot.bin
>
> +%.o: %.S
> + $(CC) -E $(CFLAGS) -o - -c $< |${LOCALBASE}/bin/as -V -Qy -o $@
> +
> %.img: %.o
> $(call quiet-command,$(LD) -Ttext 0 -e _start -s -o $@ $<," Building $(TARGET_DIR)$@")
>
That patch didn't seem to help on OpenBSD so I now finally got around
making another one that just emits the bytes of the offending insn
instead so people can keep using old assemblers:
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
cc-option uses more make-syntax to replace the shell "if/else".
Issue with recursive += is fixed by doing the first assignment
simply-expanded, as explained in
http://www.gnu.org/software/make/manual/html_node/Appending.html
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
With cc-option we are testing if gcc just accept a particular option, we don't need CFLAGS at all. And this fixes the recursive problem with CFLAGS
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Now we have to variables: QEMU_CFLAGS: flags without which we can't compile
CFLAGS: "-g -O2"
We can now run:
make CFLAGS="-fbar" foo.o
make CFLAGS="" foo.o
make CFLAGS="-O3" foo.o
And it all should work.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-Id:
The printf command takes an octal value after \, so we have to convert
our decimal representation to octal first and then write it.
This unbreaks extboot signing. Multiboot wasn't affected yet because
the checksum was < 8.
Spotted and first patch by Glauber Costa <glommer@redhat.com>.
Printf idea by Paolo Bonzini <bonzini@gnu.org>.
Signed-off-by: Alexander Graf <agraf@suse.de>
CC: Glauber Costa <glommer@redhat.com>
CC: Paolo Bonzini <bonzini@gnu.org>
CC: Jan Ondrej <ondrejj@salstar.sk>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-Id:
Attached patch makes signrom.sh working on NetBSD.
The output of the 'od' command leads to a syntax error
which breaks the build.
Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In order to not execute code we just compiled, let's replace signrom
with a shell script that does the same thing while staying compatible
to pretty much every system available.
This should make cross-compilation for windows easier.
aliguori: fix build when objdir != srcdir
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In order to build the multiboot option rom, we need a Makefile and a tool
to sign the rom with.
Both are provided by this patch and mostly taken from the extboot source,
written by Anthony Liguori.
Once built, the resulting binary gets copied to pc-bios automatically.
Building also occurs automatically when on an x86 host.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This patch implements support for Multiboot on x86 for -kernel.
Multiboot is a "new" approach to get rid of different bootloaders, providing
a unified interface for the kernel. It supports command line options and
kernel modules.
The two probably best known projects using multiboot are Xen and GNU Hurd.
This implementation should be mostly feature-complete. It is missing VBE
extensions, but as no system uses them currently it does not really hurt.
To use multiboot, specify the kernel as -kernel option. Modules should be given
as -initrd options, seperated by a comma (,). -append also works.
Please bear in mind that grub also does gzip decompression, which qemu does
not do yet. To run existing images, please ungzip them first.
The guest multiboot loader code is implemented as option rom using int 19.
Parts of the work are based on efforts by Rene Rebe, who originally ported
my code to int 19.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
