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-rw-r--r--Documentation/x86/boot.txt32
-rw-r--r--arch/x86/boot/header.S6
-rw-r--r--arch/x86/include/asm/acpi.h7
-rw-r--r--arch/x86/include/asm/x86_init.h2
-rw-r--r--arch/x86/include/uapi/asm/bootparam.h4
-rw-r--r--arch/x86/kernel/acpi/boot.c6
-rw-r--r--arch/x86/kernel/head32.c1
-rw-r--r--arch/x86/kernel/head64.c2
-rw-r--r--arch/x86/kernel/setup.c17
-rw-r--r--arch/x86/kernel/x86_init.c3
-rw-r--r--arch/x86/xen/enlighten_pvh.c2
11 files changed, 77 insertions, 5 deletions
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index 5e9b826b5f62..7727db8f94bc 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -61,6 +61,18 @@ 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
+
+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
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 850b8762e889..4c881c850125 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 the
+ # ACPI RSDP table, added with
+ # version 2.14
+
# End of setup header #####################################################
.section ".entrytext", "ax"
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index a303d7b7d763..2f01eb4d6208 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -142,6 +142,8 @@ static inline u64 acpi_arch_get_root_pointer(void)
void acpi_generic_reduced_hw_init(void);
+u64 x86_default_get_root_pointer(void);
+
#else /* !CONFIG_ACPI */
#define acpi_lapic 0
@@ -153,6 +155,11 @@ static inline void disable_acpi(void) { }
static inline void acpi_generic_reduced_hw_init(void) { }
+static inline u64 x86_default_get_root_pointer(void)
+{
+ return 0;
+}
+
#endif /* !CONFIG_ACPI */
#define ARCH_HAS_POWER_INIT 1
diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
index b85a7c54c6a1..0f842104862c 100644
--- a/arch/x86/include/asm/x86_init.h
+++ b/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
diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index a06cbf019744..22f89d040ddd 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/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 {
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 3b20607d581b..e8fea7ffa306 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -48,6 +48,7 @@
#include <asm/mpspec.h>
#include <asm/smp.h>
#include <asm/i8259.h>
+#include <asm/setup.h>
#include "sleep.h" /* To include x86_acpi_suspend_lowlevel */
static int __initdata acpi_force = 0;
@@ -1771,3 +1772,8 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
e820__range_add(addr, size, E820_TYPE_ACPI);
e820__update_table_print();
}
+
+u64 x86_default_get_root_pointer(void)
+{
+ return boot_params.hdr.acpi_rsdp_addr;
+}
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index ec6fefbfd3c0..76fa3b836598 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -37,6 +37,7 @@ asmlinkage __visible void __init i386_start_kernel(void)
cr4_init_shadow();
sanitize_boot_params(&boot_params);
+ x86_verify_bootdata_version();
x86_early_init_platform_quirks();
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index ddee1f0870c4..5dc377dc9d7b 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -457,6 +457,8 @@ void __init x86_64_start_reservations(char *real_mode_data)
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) {
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 90ecc108bc8a..7005f89bf3b2 100644
--- a/arch/x86/kernel/setup.c
+++ b/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 = {
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 2792b5573818..50a2b492fdd6 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -31,7 +31,6 @@ static int __init iommu_init_noop(void) { return 0; }
static void iommu_shutdown_noop(void) { }
static bool __init bool_x86_init_noop(void) { return false; }
static void x86_op_int_noop(int cpu) { }
-static u64 u64_x86_init_noop(void) { return 0; }
/*
* The platform setup functions are preset with the default functions
@@ -96,7 +95,7 @@ struct x86_init_ops x86_init __initdata = {
},
.acpi = {
- .get_root_pointer = u64_x86_init_noop,
+ .get_root_pointer = x86_default_get_root_pointer,
.reduced_hw_early_init = acpi_generic_reduced_hw_init,
},
};
diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index 2a9025343534..02e3ab7ff242 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -76,7 +76,7 @@ static void __init init_pvh_bootparams(void)
* Version 2.12 supports Xen entry point but we will use default x86/PC
* environment (i.e. hardware_subarch 0).
*/
- pvh_bootparams.hdr.version = 0x212;
+ pvh_bootparams.hdr.version = (2 << 8) | 12;
pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
x86_init.acpi.get_root_pointer = pvh_get_root_pointer;