* Juergen Gross <jgross@xxxxxxxx> wrote: > Xen PVH guests receive the address of the RSDP table from Xen. In order > to support booting a Xen PVH guest via grub2 using the standard x86 > boot entry we need a way fro grub2 to pass the RSDP address to the > kernel. > > For this purpose expand the struct setup_header to hold the physical > address of the RSDP address. Being zero means it isn't specified and > has to be located the legacy way (searching through low memory or > EBDA). s/fro /for pedantry: s/grub2 /Grub2 > Signed-off-by: Juergen Gross <jgross@xxxxxxxx> > Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> > --- > Documentation/x86/boot.txt | 19 +++++++++++++++++++ > arch/x86/boot/header.S | 6 +++++- > arch/x86/include/uapi/asm/bootparam.h | 1 + > 3 files changed, 25 insertions(+), 1 deletion(-) > > diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt > index 5e9b826b5f62..a33c224797e4 100644 > --- a/Documentation/x86/boot.txt > +++ b/Documentation/x86/boot.txt > @@ -61,6 +61,13 @@ Protocol 2.12: (Kernel 3.8) Added the xloadflags field and extension fields > to struct boot_params for loading bzImage and ramdisk > above 4G in 64bit. > > +Protocol 2.13: (Kernel 3.14) Support 32- and 64-bit flags being set in > + xloadflags to support booting a 64 bit kernel from 32 bit > + EFI The changelog should I think declare that we add documentation for the 2.13 protocol iteration as well. Also, please use a consistent spelling of '32-bit' and '64-bit' in the same sentence! > +Field name: acpi_rsdp_addr > +Type: write > +Offset/size: 0x268/8 > +Protocol: 2.14+ > + > + This field can be set by the boot loader to tell the kernel the > + physical address of the ACPI RSDP table. > + > + A value of 0 indicates the kernel should fall back to the standard > + methods to locate the RSDP (search in EBDA/low memory). That's not the only method used: the ACPI RSDP address can also be discovered via efi.rsdp20 and efi.rsdp, both of which appear to be 32-bit values. > **** THE IMAGE CHECKSUM > > diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S > index 850b8762e889..e7184127f309 100644 > --- a/arch/x86/boot/header.S > +++ b/arch/x86/boot/header.S > @@ -300,7 +300,7 @@ _start: > # Part 2 of the header, from the old setup.S > > .ascii "HdrS" # header signature > - .word 0x020d # header version number (>= 0x0105) > + .word 0x020e # header version number (>= 0x0105) > # or else old loadlin-1.5 will fail) > .globl realmode_swtch > realmode_swtch: .word 0, 0 # default_switch, SETUPSEG > @@ -558,6 +558,10 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr > init_size: .long INIT_SIZE # kernel initialization size > handover_offset: .long 0 # Filled in by build.c > > +acpi_rsdp_addr: .quad 0 # 64-bit physical pointer to > + # ACPI RSDP table, added with > + # version 2.14 s/pointer to ACPI RSDP table /pointer to the ACPI RSDP table Also, a more fundamental question: why doesn't Xen use EFI to hand over hardware configuration details? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
