diff options
Diffstat (limited to 'debian/patches/features/x86/x86-boot-Add-ACPI-RSDP-address-to-setup_header.patch')
| -rw-r--r-- | debian/patches/features/x86/x86-boot-Add-ACPI-RSDP-address-to-setup_header.patch | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/debian/patches/features/x86/x86-boot-Add-ACPI-RSDP-address-to-setup_header.patch b/debian/patches/features/x86/x86-boot-Add-ACPI-RSDP-address-to-setup_header.patch new file mode 100644 index 000000000..55b116db9 --- /dev/null +++ b/debian/patches/features/x86/x86-boot-Add-ACPI-RSDP-address-to-setup_header.patch @@ -0,0 +1,232 @@ +From: Juergen Gross <jgross@suse.com> +Date: Wed, 10 Oct 2018 08:14:55 +0200 +Subject: x86/boot: Add ACPI RSDP address to setup_header +Origin: https://git.kernel.org/linus/ae7e1238e68f2a472a125673ab506d49158c1889 + +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 for 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). + +While documenting the new setup_header layout and protocol version +2.14 add the missing documentation of protocol version 2.13. + +There are Grub2 versions in several distros with a downstream patch +violating the boot protocol by writing past the end of setup_header. +This requires another update of the boot protocol to enable the kernel +to distinguish between a specified RSDP address and one filled with +garbage by such a broken Grub2. + +From protocol 2.14 on Grub2 will write the version it is supporting +(but never a higher value than found to be supported by the kernel) +ored with 0x8000 to the version field of setup_header. This enables +the kernel to know up to which field Grub2 has written information +to. All fields after that are supposed to be clobbered. + +Signed-off-by: Juergen Gross <jgross@suse.com> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Thomas Gleixner <tglx@linutronix.de> +Cc: boris.ostrovsky@oracle.com +Cc: bp@alien8.de +Cc: corbet@lwn.net +Cc: linux-doc@vger.kernel.org +Cc: xen-devel@lists.xenproject.org +Link: http://lkml.kernel.org/r/20181010061456.22238-3-jgross@suse.com +Signed-off-by: Ingo Molnar <mingo@kernel.org> +--- + Documentation/x86/boot.txt | 32 ++++++++++++++++++++++++++- + arch/x86/boot/header.S | 6 ++++- + arch/x86/include/asm/x86_init.h | 2 ++ + arch/x86/include/uapi/asm/bootparam.h | 4 ++++ + arch/x86/kernel/head32.c | 1 + + arch/x86/kernel/head64.c | 2 ++ + arch/x86/kernel/setup.c | 17 ++++++++++++++ + 7 files changed, 62 insertions(+), 2 deletions(-) + +Index: linux/Documentation/x86/boot.txt +=================================================================== +--- linux.orig/Documentation/x86/boot.txt ++++ linux/Documentation/x86/boot.txt +@@ -61,6 +61,18 @@ Protocol 2.12: (Kernel 3.8) Added the xl + 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 ++ ++Protocol 2.14: (Kernel 4.20) Added acpi_rsdp_addr holding the physical ++ address of the ACPI RSDP table. ++ The bootloader updates version with: ++ 0x8000 | min(kernel-version, bootloader-version) ++ kernel-version being the protocol version supported by ++ the kernel and bootloader-version the protocol version ++ supported by the bootloader. ++ + **** MEMORY LAYOUT + + The traditional memory map for the kernel loader, used for Image or +@@ -197,6 +209,7 @@ Offset Proto Name Meaning + 0258/8 2.10+ pref_address Preferred loading address + 0260/4 2.10+ init_size Linear memory required during initialization + 0264/4 2.11+ handover_offset Offset of handover entry point ++0268/8 2.14+ acpi_rsdp_addr Physical address of RSDP table + + (1) For backwards compatibility, if the setup_sects field contains 0, the + real value is 4. +@@ -309,7 +322,7 @@ Protocol: 2.00+ + Contains the magic number "HdrS" (0x53726448). + + Field name: version +-Type: read ++Type: modify + Offset/size: 0x206/2 + Protocol: 2.00+ + +@@ -317,6 +330,12 @@ Protocol: 2.00+ + e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version + 10.17. + ++ Up to protocol version 2.13 this information is only read by the ++ bootloader. From protocol version 2.14 onwards the bootloader will ++ write the used protocol version or-ed with 0x8000 to the field. The ++ used protocol version will be the minimum of the supported protocol ++ versions of the bootloader and the kernel. ++ + Field name: realmode_swtch + Type: modify (optional) + Offset/size: 0x208/4 +@@ -744,6 +763,17 @@ Offset/size: 0x264/4 + + See EFI HANDOVER PROTOCOL below for more details. + ++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. ++ + + **** THE IMAGE CHECKSUM + +Index: linux/arch/x86/boot/header.S +=================================================================== +--- linux.orig/arch/x86/boot/header.S ++++ linux/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 + 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 the ++ # ACPI RSDP table, added with ++ # version 2.14 ++ + # End of setup header ##################################################### + + .section ".entrytext", "ax" +Index: linux/arch/x86/include/asm/x86_init.h +=================================================================== +--- linux.orig/arch/x86/include/asm/x86_init.h ++++ linux/arch/x86/include/asm/x86_init.h +@@ -303,4 +303,6 @@ extern void x86_init_noop(void); + extern void x86_init_uint_noop(unsigned int unused); + extern bool x86_pnpbios_disabled(void); + ++void x86_verify_bootdata_version(void); ++ + #endif +Index: linux/arch/x86/include/uapi/asm/bootparam.h +=================================================================== +--- linux.orig/arch/x86/include/uapi/asm/bootparam.h ++++ linux/arch/x86/include/uapi/asm/bootparam.h +@@ -16,6 +16,9 @@ + #define RAMDISK_PROMPT_FLAG 0x8000 + #define RAMDISK_LOAD_FLAG 0x4000 + ++/* version flags */ ++#define VERSION_WRITTEN 0x8000 ++ + /* loadflags */ + #define LOADED_HIGH (1<<0) + #define KASLR_FLAG (1<<1) +@@ -86,6 +89,7 @@ struct setup_header { + __u64 pref_address; + __u32 init_size; + __u32 handover_offset; ++ __u64 acpi_rsdp_addr; + } __attribute__((packed)); + + struct sys_desc_table { +Index: linux/arch/x86/kernel/head32.c +=================================================================== +--- linux.orig/arch/x86/kernel/head32.c ++++ linux/arch/x86/kernel/head32.c +@@ -37,6 +37,7 @@ asmlinkage __visible void __init i386_st + cr4_init_shadow(); + + sanitize_boot_params(&boot_params); ++ x86_verify_bootdata_version(); + + x86_early_init_platform_quirks(); + +Index: linux/arch/x86/kernel/head64.c +=================================================================== +--- linux.orig/arch/x86/kernel/head64.c ++++ linux/arch/x86/kernel/head64.c +@@ -477,6 +477,8 @@ void __init x86_64_start_reservations(ch + if (!boot_params.hdr.version) + copy_bootdata(__va(real_mode_data)); + ++ x86_verify_bootdata_version(); ++ + x86_early_init_platform_quirks(); + + switch (boot_params.hdr.hardware_subarch) { +Index: linux/arch/x86/kernel/setup.c +=================================================================== +--- linux.orig/arch/x86/kernel/setup.c ++++ linux/arch/x86/kernel/setup.c +@@ -1281,6 +1281,23 @@ void __init setup_arch(char **cmdline_p) + unwind_init(); + } + ++/* ++ * From boot protocol 2.14 onwards we expect the bootloader to set the ++ * version to "0x8000 | <used version>". In case we find a version >= 2.14 ++ * without the 0x8000 we assume the boot loader supports 2.13 only and ++ * reset the version accordingly. The 0x8000 flag is removed in any case. ++ */ ++void __init x86_verify_bootdata_version(void) ++{ ++ if (boot_params.hdr.version & VERSION_WRITTEN) ++ boot_params.hdr.version &= ~VERSION_WRITTEN; ++ else if (boot_params.hdr.version >= 0x020e) ++ boot_params.hdr.version = 0x020d; ++ ++ if (boot_params.hdr.version < 0x020e) ++ boot_params.hdr.acpi_rsdp_addr = 0; ++} ++ + #ifdef CONFIG_X86_32 + + static struct resource video_ram_resource = { |