Add a new option rom for the multiboot loader, using DMA transfers to copy
data instead of "rep insb".
This significantly lowers QEMU's startup latency by a factor of about 40,
for example, going from 30sec to 0.8sec when loading modules of 120MB
in size.
Signed-off-by: Marcus Hähnel <marcus.haehnel@kernkonzept.com>
Signed-off-by: Adam Lackorzynski <adam@l4re.org>
[Modified to keep the non-DMA code depending on #ifdef USE_FW_CFG_DMA;
do not write below stack. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The upper_mem field of the Multiboot information struct doesn't really
contain the RAM size - 1 MB like we used to calculate it, but only the
memory from 1 MB up to the first (upper) memory hole.
In order to correctly retrieve this information, the multiboot ROM now
looks at the mmap it creates anyway and tries to find the size of
contiguous usable memory from 1 MB.
Drop the multiboot.c definition of lower_mem and upper_mem because both
are queried at runtime now.
Signed-off-by: Kevin Wolf <mail@kevin-wolf.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1372018066-21822-3-git-send-email-mail@kevin-wolf.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
When the BIOS returns ebx = 0, the current entry is still valid and
needs to be included in the Multiboot memory map.
Fixing this meant that using bx as the entry index doesn't work any
more because it's 0 on the last entry (and it was SeaBIOS-specific
anyway), so the whole loop had to change a bit and should be more
generic as a result (ebx can be an arbitrary continuation number now,
and the entry size returned by the BIOS is used instead of hard-coding
20 bytes).
Signed-off-by: Kevin Wolf <mail@kevin-wolf.de>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1372018066-21822-2-git-send-email-mail@kevin-wolf.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The e801 memory sizes in the multiboot structures hard-code the available
low memory to 640. However, the value should not include the size of the
EBDA. Fill the value in the option ROM, getting the size of low memory
from the BIOS.
Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
accidently->accidentally
annother->another
choosen->chosen
consideres->considers
decriptor->descriptor
developement->development
paramter->parameter
preceed->precede
preceeding->preceding
priviledge->privilege
propogation->propagation
substraction->subtraction
throught->through
upto->up to
usefull->useful
Fix also grammar in posix-aio-compat.c
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Currently linuxboot.bin and multiboot.bin option roms override int19
vector to intercept boot process. No sane option rom should do that.
Provide bev entry instead that will be called by BIOS if option rom
is selected for booting.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
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>
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>
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>
