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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/page.h>
#include <asm/msr.h>
.text
.code32
#undef bootsym_phys
#define sym_phys(sym) ((sym) - __XEN_VIRT_START)
#define bootsym_phys(sym) ((sym) - trampoline_start + BOOT_TRAMPOLINE)
#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
.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
/* Save the Multiboot info structure for later use. */
mov %ebx,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)+CPUINFO_ext_features
#if defined(__x86_64__)
/* Check for availability of long mode. */
bt $29,%edx
jnc bad_cpu
/* Initialise L2 identity-map and xen page table entries (16MB). */
mov $sym_phys(l2_identmap),%edi
mov $sym_phys(l2_xenmap),%esi
mov $0x1e3,%eax /* PRESENT+RW+A+D+2MB+GLOBAL */
mov $8,%ecx
1: mov %eax,(%edi)
add $8,%edi
mov %eax,(%esi)
add $8,%esi
add $(1<<L2_PAGETABLE_SHIFT),%eax
loop 1b
/* Initialise L3 identity-map page directory entries. */
mov $sym_phys(l3_identmap),%edi
mov $(sym_phys(l2_identmap)+7),%eax
mov $4,%ecx
1: mov %eax,(%edi)
add $8,%edi
add $PAGE_SIZE,%eax
loop 1b
/* Initialise L3 xen-map page directory entry. */
mov $(sym_phys(l2_xenmap)+7),%eax
mov %eax,sym_phys(l3_xenmap) + (50*8)
/* Hook identity-map and xen-map L3 tables into PML4. */
mov $(sym_phys(l3_identmap)+7),%eax
mov %eax,sym_phys(idle_pg_table) + ( 0*8) /* PML4[ 0]: 1:1 map */
mov %eax,sym_phys(idle_pg_table) + (262*8) /* PML4[262]: 1:1 map */
mov $(sym_phys(l3_xenmap)+7),%eax
mov %eax,sym_phys(idle_pg_table) + (261*8) /* PML4[261]: xen map */
#elif defined(CONFIG_X86_PAE)
/* Initialize low and high mappings of memory with 2MB pages */
mov $sym_phys(idle_pg_table_l2),%edi
mov $0xe3,%eax /* PRESENT+RW+A+D+2MB */
1: mov %eax,__PAGE_OFFSET>>18(%edi) /* high mapping */
stosl /* low mapping */
add $4,%edi
add $(1<<L2_PAGETABLE_SHIFT),%eax
cmp $DIRECTMAP_PHYS_END+0xe3,%eax
jne 1b
1: stosl /* low mappings cover up to 16MB */
add $4,%edi
add $(1<<L2_PAGETABLE_SHIFT),%eax
cmp $(16<<20)+0xe3,%eax
jne 1b
#else
/* Initialize low and high mappings of memory with 4MB pages */
mov $sym_phys(idle_pg_table),%edi
mov $0xe3,%eax /* PRESENT+RW+A+D+4MB */
1: mov %eax,__PAGE_OFFSET>>20(%edi) /* high mapping */
stosl /* low mapping */
add $(1<<L2_PAGETABLE_SHIFT),%eax
cmp $DIRECTMAP_PHYS_END+0xe3,%eax
jne 1b
1: stosl /* low mappings cover up to 16MB */
add $(1<<L2_PAGETABLE_SHIFT),%eax
cmp $(16<<20)+0xe3,%eax
jne 1b
#endif
/* Initialize 4kB mappings of first 2MB or 4MB of memory. */
mov $sym_phys(l1_identmap),%edi
mov $0x263,%eax /* PRESENT+RW+A+D+SMALL_PAGES */
#if defined(__x86_64__)
or $0x100,%eax /* GLOBAL */
#endif
xor %ecx,%ecx
1: stosl
#if CONFIG_PAGING_LEVELS >= 3
add $4,%edi
#endif
add $PAGE_SIZE,%eax
inc %ecx
/* VGA hole (0xa0000-0xc0000) should be mapped UC. */
cmp $0xa0,%ecx
jne 2f
or $0x10,%eax /* +PCD */
2: cmp $0xc0,%ecx
jne 2f
and $~0x10,%eax /* -PCD */
2: cmp $L1_PAGETABLE_ENTRIES,%ecx
jne 1b
sub $(PAGE_SIZE-0x63),%edi
#if defined(__x86_64__)
mov %edi,sym_phys(l2_identmap)
mov %edi,sym_phys(l2_xenmap)
#elif defined(CONFIG_X86_PAE)
mov %edi,sym_phys(idle_pg_table_l2)
mov %edi,sym_phys(idle_pg_table_l2) + (__PAGE_OFFSET>>18)
#else
mov %edi,sym_phys(idle_pg_table)
mov %edi,sym_phys(idle_pg_table) + (__PAGE_OFFSET>>20)
#endif
/* Copy bootstrap trampoline to low memory, below 1MB. */
mov $sym_phys(trampoline_start),%esi
mov $bootsym_phys(trampoline_start),%edi
mov $trampoline_end - trampoline_start,%ecx
rep movsb
mov $bootsym_phys(early_stack),%esp
call cmdline_parse_early
/* Jump into the relocated trampoline. */
jmp $BOOT_CS32,$bootsym_phys(trampoline_boot_cpu_entry)
#include "cmdline.S"
.align 16
.globl trampoline_start, trampoline_end
trampoline_start:
#include "trampoline.S"
trampoline_end:
.text
__high_start:
#ifdef __x86_64__
#include "x86_64.S"
#else
#include "x86_32.S"
#endif
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