f37240f16b
Added header for trampoline code that can be used to supply input data to it. This makes interface between real mode code and kernel cleaner and simpler. Replaced two confusing pointers to level4 pgt in trampoline_64.S with a single pointer to the beginning of the page table. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
67 lines
1.7 KiB
ArmAsm
67 lines
1.7 KiB
ArmAsm
/*
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*
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* Trampoline.S Derived from Setup.S by Linus Torvalds
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*
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* 4 Jan 1997 Michael Chastain: changed to gnu as.
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*
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* This is only used for booting secondary CPUs in SMP machine
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*
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* Entry: CS:IP point to the start of our code, we are
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* in real mode with no stack, but the rest of the
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* trampoline page to make our stack and everything else
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* is a mystery.
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*
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* We jump into arch/x86/kernel/head_32.S.
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*
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* On entry to trampoline_start, the processor is in real mode
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* with 16-bit addressing and 16-bit data. CS has some value
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* and IP is zero. Thus, we load CS to the physical segment
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* of the real mode code before doing anything further.
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*/
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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <asm/segment.h>
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#include <asm/page_types.h>
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#include "realmode.h"
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.text
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.code16
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.balign PAGE_SIZE
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ENTRY(trampoline_start)
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wbinvd # Needed for NUMA-Q should be harmless for others
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LJMPW_RM(1f)
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1:
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mov %cs, %ax # Code and data in the same place
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mov %ax, %ds
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cli # We should be safe anyway
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movl tr_start, %eax # where we need to go
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movl $0xA5A5A5A5, trampoline_status
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# write marker for master knows we're running
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/*
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* GDT tables in non default location kernel can be beyond 16MB and
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* lgdt will not be able to load the address as in real mode default
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* operand size is 16bit. Use lgdtl instead to force operand size
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* to 32 bit.
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*/
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lidtl tr_idt # load idt with 0, 0
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lgdtl tr_gdt # load gdt with whatever is appropriate
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movw $1, %dx # protected mode (PE) bit
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lmsw %dx # into protected mode
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ljmpl $__BOOT_CS, $pa_startup_32
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.section ".text32","ax"
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.code32
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ENTRY(startup_32) # note: also used from wakeup_asm.S
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jmp *%eax
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#include "trampoline_common.S"
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