diff options
Diffstat (limited to 'arch/i386/kernel/head.S')
| -rw-r--r-- | arch/i386/kernel/head.S | 68 |
1 files changed, 62 insertions, 6 deletions
diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index be9d883c62c..edef5084ce1 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -55,6 +55,12 @@ */ ENTRY(startup_32) +#ifdef CONFIG_PARAVIRT + movl %cs, %eax + testl $0x3, %eax + jnz startup_paravirt +#endif + /* * Set segments to known values. */ @@ -302,6 +308,7 @@ is386: movl $2,%ecx # set MP movl %eax,%cr0 call check_x87 + call setup_pda lgdt cpu_gdt_descr lidt idt_descr ljmp $(__KERNEL_CS),$1f @@ -312,12 +319,15 @@ is386: movl $2,%ecx # set MP movl %eax,%ds movl %eax,%es - xorl %eax,%eax # Clear FS/GS and LDT + xorl %eax,%eax # Clear FS and LDT movl %eax,%fs - movl %eax,%gs lldt %ax + + movl $(__KERNEL_PDA),%eax + mov %eax,%gs + cld # gcc2 wants the direction flag cleared at all times - pushl %eax # fake return address + pushl $0 # fake return address for unwinder #ifdef CONFIG_SMP movb ready, %cl movb $1, ready @@ -346,6 +356,23 @@ check_x87: ret /* + * Point the GDT at this CPU's PDA. On boot this will be + * cpu_gdt_table and boot_pda; for secondary CPUs, these will be + * that CPU's GDT and PDA. + */ +setup_pda: + /* get the PDA pointer */ + movl start_pda, %eax + + /* slot the PDA address into the GDT */ + mov cpu_gdt_descr+2, %ecx + mov %ax, (__KERNEL_PDA+0+2)(%ecx) /* base & 0x0000ffff */ + shr $16, %eax + mov %al, (__KERNEL_PDA+4+0)(%ecx) /* base & 0x00ff0000 */ + mov %ah, (__KERNEL_PDA+4+3)(%ecx) /* base & 0xff000000 */ + ret + +/* * setup_idt * * sets up a idt with 256 entries pointing to @@ -465,6 +492,33 @@ ignore_int: #endif iret +#ifdef CONFIG_PARAVIRT +startup_paravirt: + cld + movl $(init_thread_union+THREAD_SIZE),%esp + + /* We take pains to preserve all the regs. */ + pushl %edx + pushl %ecx + pushl %eax + + /* paravirt.o is last in link, and that probe fn never returns */ + pushl $__start_paravirtprobe +1: + movl 0(%esp), %eax + pushl (%eax) + movl 8(%esp), %eax + call *(%esp) + popl %eax + + movl 4(%esp), %eax + movl 8(%esp), %ecx + movl 12(%esp), %edx + + addl $4, (%esp) + jmp 1b +#endif + /* * Real beginning of normal "text" segment */ @@ -484,6 +538,8 @@ ENTRY(empty_zero_page) * This starts the data section. */ .data +ENTRY(start_pda) + .long boot_pda ENTRY(stack_start) .long init_thread_union+THREAD_SIZE @@ -525,7 +581,7 @@ idt_descr: # boot GDT descriptor (later on used by CPU#0): .word 0 # 32 bit align gdt_desc.address -cpu_gdt_descr: +ENTRY(cpu_gdt_descr) .word GDT_ENTRIES*8-1 .long cpu_gdt_table @@ -584,8 +640,8 @@ ENTRY(cpu_gdt_table) .quad 0x00009a000000ffff /* 0xc0 APM CS 16 code (16 bit) */ .quad 0x004092000000ffff /* 0xc8 APM DS data */ - .quad 0x0000920000000000 /* 0xd0 - ESPFIX 16-bit SS */ - .quad 0x0000000000000000 /* 0xd8 - unused */ + .quad 0x00c0920000000000 /* 0xd0 - ESPFIX SS */ + .quad 0x00cf92000000ffff /* 0xd8 - PDA */ .quad 0x0000000000000000 /* 0xe0 - unused */ .quad 0x0000000000000000 /* 0xe8 - unused */ .quad 0x0000000000000000 /* 0xf0 - unused */ |