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#include <xen/config.h>
#include <xen/multiboot.h>
#include <public/xen.h>
#include <asm/asm_defns.h>
#include <asm/desc.h>
#include <asm/fixmap.h>
#include <asm/page.h>
#include <asm/msr.h>
.text
.code32
#define sym_phys(sym) ((sym) - __XEN_VIRT_START)
#define BOOT_CS32 0x0008
#define BOOT_CS64 0x0010
#define BOOT_DS 0x0018
#define BOOT_PSEUDORM_CS 0x0020
#define BOOT_PSEUDORM_DS 0x0028
ENTRY(start)
jmp __start
.align 4
/*** MULTIBOOT HEADER ****/
#define MULTIBOOT_HEADER_FLAGS (MULTIBOOT_HEADER_MODS_ALIGNED | \
MULTIBOOT_HEADER_WANT_MEMORY)
/* Magic number indicating a Multiboot header. */
.long MULTIBOOT_HEADER_MAGIC
/* Flags to bootloader (see Multiboot spec). */
.long MULTIBOOT_HEADER_FLAGS
/* Checksum: must be the negated sum of the first two fields. */
.long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)
.section .init.text, "ax"
.Lbad_cpu_msg: .asciz "ERR: Not a 64-bit CPU!"
.Lbad_ldr_msg: .asciz "ERR: Not a Multiboot bootloader!"
bad_cpu:
mov $(sym_phys(.Lbad_cpu_msg)),%esi # Error message
jmp print_err
not_multiboot:
mov $(sym_phys(.Lbad_ldr_msg)),%esi # Error message
print_err:
mov $0xB8000,%edi # VGA framebuffer
1: mov (%esi),%bl
test %bl,%bl # Terminate on '\0' sentinel
2: je 2b
mov $0x3f8+5,%dx # UART Line Status Register
3: in %dx,%al
test $0x20,%al # Test THR Empty flag
je 3b
mov $0x3f8+0,%dx # UART Transmit Holding Register
mov %bl,%al
out %al,%dx # Send a character over the serial line
movsb # Write a character to the VGA framebuffer
mov $7,%al
stosb # Write an attribute to the VGA framebuffer
jmp 1b
gdt_boot_descr:
.word 6*8-1
.long sym_phys(trampoline_gdt)
__start:
cld
cli
/* Initialise GDT and basic data segments. */
lgdt %cs:sym_phys(gdt_boot_descr)
mov $BOOT_DS,%ecx
mov %ecx,%ds
mov %ecx,%es
mov %ecx,%ss
/* Check for Multiboot bootloader */
cmp $0x2BADB002,%eax
jne not_multiboot
/* Set up trampoline segment 64k below EBDA */
movzwl 0x40e,%eax /* EBDA segment */
cmp $0xa000,%eax /* sanity check (high) */
jae 0f
cmp $0x4000,%eax /* sanity check (low) */
jae 1f
0:
movzwl 0x413,%eax /* use base memory size on failure */
shl $10-4,%eax
1:
/*
* Compare the value in the BDA with the information from the
* multiboot structure (if available) and use the smallest.
*/
testb $MBI_MEMLIMITS,(%ebx)
jz 2f /* not available? BDA value will be fine */
mov 4(%ebx),%edx
cmp $0x100,%edx /* is the multiboot value too small? */
jb 2f /* if so, do not use it */
shl $10-4,%edx
cmp %eax,%edx /* compare with BDA value */
cmovb %edx,%eax /* and use the smaller */
2: /* Reserve 64kb for the trampoline */
sub $0x1000,%eax
/* From arch/x86/smpboot.c: start_eip had better be page-aligned! */
xor %al, %al
shl $4, %eax
mov %eax,sym_phys(trampoline_phys)
/* Save the Multiboot info struct (after relocation) for later use. */
mov $sym_phys(cpu0_stack)+1024,%esp
push %ebx
call reloc
mov %eax,sym_phys(multiboot_ptr)
/* Initialize BSS (no nasty surprises!) */
mov $sym_phys(__bss_start),%edi
mov $sym_phys(_end),%ecx
sub %edi,%ecx
xor %eax,%eax
rep stosb
/* Interrogate CPU extended features via CPUID. */
mov $0x80000000,%eax
cpuid
xor %edx,%edx
cmp $0x80000000,%eax # any function > 0x80000000?
jbe 1f
mov $0x80000001,%eax
cpuid
1: mov %edx,sym_phys(cpuid_ext_features)
mov %edx,sym_phys(boot_cpu_data)+CPUINFO86_ext_features
/* Check for availability of long mode. */
bt $29,%edx
jnc bad_cpu
/* Initialise L2 boot-map page table entries (16MB). */
mov $sym_phys(l2_bootmap),%edx
mov $PAGE_HYPERVISOR|_PAGE_PSE,%eax
mov $8,%ecx
1: mov %eax,(%edx)
add $8,%edx
add $(1<<L2_PAGETABLE_SHIFT),%eax
loop 1b
/* Initialise L3 boot-map page directory entry. */
mov $sym_phys(l2_bootmap)+__PAGE_HYPERVISOR,%eax
mov %eax,sym_phys(l3_bootmap) + 0*8
/* Hook 4kB mappings of first 2MB of memory into L2. */
mov $sym_phys(l1_identmap)+__PAGE_HYPERVISOR,%edi
mov %edi,sym_phys(l2_xenmap)
mov %edi,sym_phys(l2_bootmap)
/* Apply relocations to bootstrap trampoline. */
mov sym_phys(trampoline_phys),%edx
mov $sym_phys(__trampoline_rel_start),%edi
mov %edx,sym_phys(trampoline_phys)
1:
mov (%edi),%eax
add %edx,(%edi,%eax)
add $4,%edi
cmp $sym_phys(__trampoline_rel_stop),%edi
jb 1b
/* Patch in the trampoline segment. */
shr $4,%edx
mov $sym_phys(__trampoline_seg_start),%edi
1:
mov (%edi),%eax
mov %dx,(%edi,%eax)
add $4,%edi
cmp $sym_phys(__trampoline_seg_stop),%edi
jb 1b
call cmdline_parse_early
/* Switch to low-memory stack. */
mov sym_phys(trampoline_phys),%edi
lea 0x10000(%edi),%esp
lea trampoline_boot_cpu_entry-trampoline_start(%edi),%eax
pushl $BOOT_CS32
push %eax
/* Copy bootstrap trampoline to low memory, below 1MB. */
mov $sym_phys(trampoline_start),%esi
mov $trampoline_end - trampoline_start,%ecx
rep movsb
/* Jump into the relocated trampoline. */
lret
#include "cmdline.S"
reloc:
#include "reloc.S"
ENTRY(trampoline_start)
#include "trampoline.S"
GLOBAL(trampoline_end)
.text
__high_start:
#include "x86_64.S"
.section .data.page_aligned, "aw", @progbits
.p2align PAGE_SHIFT
/*
* Mapping of first 2 megabytes of memory. This is mapped with 4kB mappings
* to avoid type conflicts with fixed-range MTRRs covering the lowest megabyte
* of physical memory. In any case the VGA hole should be mapped with type UC.
*/
GLOBAL(l1_identmap)
pfn = 0
.rept L1_PAGETABLE_ENTRIES
/* VGA hole (0xa0000-0xc0000) should be mapped UC. */
.if pfn >= 0xa0 && pfn < 0xc0
.long (pfn << PAGE_SHIFT) | PAGE_HYPERVISOR_NOCACHE | MAP_SMALL_PAGES
.else
.long (pfn << PAGE_SHIFT) | PAGE_HYPERVISOR | MAP_SMALL_PAGES
.endif
.long 0
pfn = pfn + 1
.endr
.size l1_identmap, . - l1_identmap
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