Commit 38418404 authored by Juergen Gross's avatar Juergen Gross Committed by Ingo Molnar

x86/boot: Mostly revert commit ae7e1238 ("Add ACPI RSDP address to setup_header")

Peter Anvin pointed out that commit:

  ae7e1238 ("x86/boot: Add ACPI RSDP address to setup_header")

should be reverted as setup_header should only contain items set by the
legacy BIOS.

So revert said commit. Instead of fully reverting the dependent commit
of:

  e7b66d16 ("x86/acpi, x86/boot: Take RSDP address for boot params if available")

just remove the setup_header reference in order to replace it by
a boot_params in a followup patch.
Suggested-by: default avatar"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: default avatarJuergen 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: daniel.kiper@oracle.com
Cc: sstabellini@kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181120072529.5489-2-jgross@suse.comSigned-off-by: Ingo Molnar's avatarIngo Molnar <mingo@kernel.org>
parent d19f9130
......@@ -61,18 +61,6 @@ 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
......@@ -209,7 +197,6 @@ 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.
......@@ -322,7 +309,7 @@ Protocol: 2.00+
Contains the magic number "HdrS" (0x53726448).
Field name: version
Type: modify
Type: read
Offset/size: 0x206/2
Protocol: 2.00+
......@@ -330,12 +317,6 @@ 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
......@@ -763,17 +744,6 @@ 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
......
......@@ -300,7 +300,7 @@ _start:
# Part 2 of the header, from the old setup.S
.ascii "HdrS" # header signature
.word 0x020e # header version number (>= 0x0105)
.word 0x020d # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
......@@ -558,10 +558,6 @@ 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"
......
......@@ -303,6 +303,4 @@ 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
......@@ -16,9 +16,6 @@
#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)
......@@ -89,7 +86,6 @@ struct setup_header {
__u64 pref_address;
__u32 init_size;
__u32 handover_offset;
__u64 acpi_rsdp_addr;
} __attribute__((packed));
struct sys_desc_table {
......
......@@ -1776,5 +1776,5 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
u64 x86_default_get_root_pointer(void)
{
return boot_params.hdr.acpi_rsdp_addr;
return 0;
}
......@@ -37,7 +37,6 @@ 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();
......
......@@ -457,8 +457,6 @@ 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) {
......
......@@ -1280,23 +1280,6 @@ 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 = {
......
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