Some cleanups for the boot path, originally inspired by an attempt to
avoid scribbling on arbitrarily-chosen low memory.
In the no-real-mode case we don't need to bounce through low memory at
all; we can run the 32-bit trampoline in-place in the Xen image.
The variables containing information which is optionally discovered by
the real-mode boot code can be put back in place in the Xen image and we
can dispense with the bootsym() pointer gymnastics in C code which
access them in low memory.
I haven't yet got to reloc(), which I think exists only to ensure that
the various breadcrumbs left all over the place by the Multiboot
bootloader aren't scribbled on when we copy the 16-bit boot trampoline
into low memory. I'd quite like to kill reloc() and pass the original
pointer up to 64-bit code to be handled in C.
That would require finding a *safe* location to put the 16-bit boot
trampoline though, which doesn't already contain anything that the
bootloader created for us.
In fact, isn't there already a chance that head.S will choose a location
for the trampoline which is already part of a module or contains one of
the Multiboot breadcrumbs?
David Woodhouse (7):
x86/wakeup: Stop using %fs for lidt/lgdt
x86/boot: Remove gratuitous call back into low-memory code
x86/boot: Only jump into low trampoline code for real-mode boot
x86/boot: Split bootsym() into four types of relocations
x86/boot: Rename trampoline_{start,end} to boot_trampoline_{start,end}
x86/boot: Copy 16-bit boot variables back up to Xen image
x86/boot: Do not use trampoline for no-real-mode boot paths
xen/arch/x86/acpi/power.c | 6 +-
xen/arch/x86/boot/edd.S | 18 ++--
xen/arch/x86/boot/head.S | 89 ++++++++++++------
xen/arch/x86/boot/mem.S | 35 +++-----
xen/arch/x86/boot/trampoline.S | 145 +++++++++++++++++++++++-------
xen/arch/x86/boot/video.S | 36 ++++----
xen/arch/x86/boot/wakeup.S | 23 ++---
xen/arch/x86/cpu/common.c | 2 +-
xen/arch/x86/cpu/intel.c | 2 +-
xen/arch/x86/efi/efi-boot.h | 31 +------
xen/arch/x86/mm.c | 2 +-
xen/arch/x86/platform_hypercall.c | 18 ++--
xen/arch/x86/setup.c | 72 ++++++++++++---
xen/arch/x86/smpboot.c | 6 +-
xen/arch/x86/tboot.c | 6 +-
xen/arch/x86/x86_64/mm.c | 2 +-
xen/arch/x86/xen.lds.S | 27 ++++--
xen/include/asm-x86/acpi.h | 2 +-
xen/include/asm-x86/config.h | 10 +--
xen/include/asm-x86/e820.h | 5 +-
xen/include/asm-x86/edd.h | 1 -
21 files changed, 339 insertions(+), 199 deletions(-)
--
2.17.2
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