Re: [SeaBIOS] placement of emulated flash [was: seabios Improved multi-platform support]
(dropping Attilio he has left Citrix). On Wed, 2013-02-20 at 23:50 +0100, Laszlo Ersek wrote: On 02/20/13 18:18, Ian Campbell wrote: On Wed, 2013-02-20 at 17:55 +0100, Laszlo Ersek wrote: However in OVMF the RESERVED_MEMBASE range is not parsed from this Xen-exported table, it is added manually in InitializeXen() [OvmfPkg/PlatformPei/Xen.c]: // // Reserve away HVMLOADER reserved memory [0xFC00,0xFD00). // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE. // AddReservedMemoryBaseSizeHob (0xFC00, 0x100); ICK, it would be far preferable for OVMF to do what SeaBIOS does and actually communicate with hvmloader IMHO. The table with XenHVMSeaBIOS signature is not created for OVMF I think; comparing the bios_config structure of function pointers between seabios.c and ovmf.c in tools/firmware/hvmloader/, the ovmf_config.bios_info_setup field is NULL. Yes. I think this should be changed then to provide a proper way for hvmloader to communicate to OVMF. It would seem sensible to follow a similar mechanism to SeaBIOS, or if possible just reuse the exact same thing (perhaps with a different signature). However there seem to be at least two info tables. Referring back, seabios_info at BIOS_INFO_PHYSICAL_ADDRESS (0x1000) is for SeaBIOS only, but hvm_info just below the end of conventional memory (at HVM_INFO_PADDR, 0x9F800) looks guest firmware independent. hvm_info is used by the toolstack to pass parameters to hvmloader itself when it starts, it is not intended to pass options from hvmloader to the bios. It is not a stable ABI struct (since hvmloader and the toolstack are a matched pair it doesn't have to be) and we hope to eventually get rid of it. Possibly hvmloader should scrub it before calling the BIOS to discourage its use. I guess the quoted range would be available from hvm_info.reserved_mem_pgstart? OvmfPkg/PlatformPei/Xen.c has a comment in XenConnect() saying /* TBD: Locate hvm_info and reserve it away. */ mXenInfo.HvmInfo = NULL; Oh dear. Is the generic approach see if you can find all what you need in hvm_info, ask for the rest in a dedicated table? (Out of pure curiosity.) As I hope is clear from the above, Nope ;-) Ian. -- Ian Campbell Everyone is entitled to an *informed* opinion. -- Harlan Ellison ___ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
[SeaBIOS] placement of emulated flash [was: seabios Improved multi-platform support]
Regarding the ACPI tables, OVMF takes them from Xen. It scans 0x000EA020 to 0x000F for the RSDP and goes from there. See OvmfPkg/AcpiPlatformDxe/Xen.c. I'm not sure about the e820 table. In hvmloader's build_e820_table() [tools/firmware/hvmloader/e820.c], a range starting at RESERVED_MEMBASE is added to the table: /* * Explicitly reserve space for special pages. * This space starts at RESERVED_MEMBASE an extends to cover various * fixed hardware mappings (e.g., LAPIC, IOAPIC, default SVGA framebuffer). * * If igd_opregion_pgbase we need to split the RESERVED region in two. */ I gather this range is found non-specially by SeaBIOS [src/xen.c] in xen_ramsize_preinit(), following the xen_seabios_info struct you mentioned, placed at 0x1000. However in OVMF the RESERVED_MEMBASE range is not parsed from this Xen-exported table, it is added manually in InitializeXen() [OvmfPkg/PlatformPei/Xen.c]: // // Reserve away HVMLOADER reserved memory [0xFC00,0xFD00). // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE. // AddReservedMemoryBaseSizeHob (0xFC00, 0x100); MemDetect.c in the same directory might be relevant as well (GetSystemMemorySizeBelow4gb(), GetSystemMemorySizeAbove4gb(); they work from the CMOS). ... I gather this is about the placement of the flash memory, yes? If a static address could work for the flash, I think in OVMF we should update - MemMapInitialization() [OvmfPkg/PlatformPei/Platform.c] - OvmfPkg/AcpiTables/Dsdt.asl But I could be completely missing the topic here... Thanks, Laszlo ___ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
Re: [SeaBIOS] placement of emulated flash [was: seabios Improved multi-platform support]
On Wed, 2013-02-20 at 17:55 +0100, Laszlo Ersek wrote: However in OVMF the RESERVED_MEMBASE range is not parsed from this Xen-exported table, it is added manually in InitializeXen() [OvmfPkg/PlatformPei/Xen.c]: // // Reserve away HVMLOADER reserved memory [0xFC00,0xFD00). // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE. // AddReservedMemoryBaseSizeHob (0xFC00, 0x100); ICK, it would be far preferable for OVMF to do what SeaBIOS does and actually communicate with hvmloader IMHO. Ian. -- Ian Campbell Current Noise: Machine Head - Blistering Whatever doesn't succeed in two months and a half in California will never succeed. -- Rev. Henry Durant, founder of the University of California ___ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
Re: [SeaBIOS] placement of emulated flash [was: seabios Improved multi-platform support]
On 02/20/13 18:18, Ian Campbell wrote: On Wed, 2013-02-20 at 17:55 +0100, Laszlo Ersek wrote: However in OVMF the RESERVED_MEMBASE range is not parsed from this Xen-exported table, it is added manually in InitializeXen() [OvmfPkg/PlatformPei/Xen.c]: // // Reserve away HVMLOADER reserved memory [0xFC00,0xFD00). // This needs to match HVMLOADER RESERVED_MEMBASE/RESERVED_MEMSIZE. // AddReservedMemoryBaseSizeHob (0xFC00, 0x100); ICK, it would be far preferable for OVMF to do what SeaBIOS does and actually communicate with hvmloader IMHO. The table with XenHVMSeaBIOS signature is not created for OVMF I think; comparing the bios_config structure of function pointers between seabios.c and ovmf.c in tools/firmware/hvmloader/, the ovmf_config.bios_info_setup field is NULL. However there seem to be at least two info tables. Referring back, seabios_info at BIOS_INFO_PHYSICAL_ADDRESS (0x1000) is for SeaBIOS only, but hvm_info just below the end of conventional memory (at HVM_INFO_PADDR, 0x9F800) looks guest firmware independent. I guess the quoted range would be available from hvm_info.reserved_mem_pgstart? OvmfPkg/PlatformPei/Xen.c has a comment in XenConnect() saying /* TBD: Locate hvm_info and reserve it away. */ mXenInfo.HvmInfo = NULL; Is the generic approach see if you can find all what you need in hvm_info, ask for the rest in a dedicated table? (Out of pure curiosity.) Thanks Laszlo ___ SeaBIOS mailing list SeaBIOS@seabios.org http://www.seabios.org/mailman/listinfo/seabios
