mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-06 02:03:52 +09:00
83d290c56f
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
96 lines
2.1 KiB
ArmAsm
96 lines
2.1 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* (C) Copyright 2014 Google, Inc
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* Copyright (C) 1991, 1992, 1993 Linus Torvalds
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*
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* Parts of this copied from Linux arch/x86/boot/compressed/head_64.S
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*/
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#include <asm/global_data.h>
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#include <asm/msr-index.h>
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#include <asm/processor-flags.h>
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.code32
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.globl cpu_call64
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cpu_call64:
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/*
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* cpu_call64(ulong pgtable, ulong setup_base, ulong target)
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*
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* eax - pgtable
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* edx - setup_base
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* ecx - target
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*/
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cli
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push %ecx /* arg2 = target */
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push %edx /* arg1 = setup_base */
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mov %eax, %ebx
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/* Load new GDT with the 64bit segments using 32bit descriptor */
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leal gdt, %eax
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movl %eax, gdt+2
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lgdt gdt
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/* Enable PAE mode */
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movl $(X86_CR4_PAE), %eax
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movl %eax, %cr4
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/* Enable the boot page tables */
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leal (%ebx), %eax
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movl %eax, %cr3
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/* Enable Long mode in EFER (Extended Feature Enable Register) */
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movl $MSR_EFER, %ecx
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rdmsr
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btsl $_EFER_LME, %eax
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wrmsr
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/* After gdt is loaded */
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xorl %eax, %eax
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lldt %ax
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movl $0x20, %eax
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ltr %ax
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/*
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* Setup for the jump to 64bit mode
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*
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* When the jump is performed we will be in long mode but
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* in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1
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* (and in turn EFER.LMA = 1). To jump into 64bit mode we use
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* the new gdt/idt that has __KERNEL_CS with CS.L = 1.
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* We place all of the values on our mini stack so lret can
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* used to perform that far jump. See the gdt below.
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*/
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pop %esi /* setup_base */
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pushl $0x10
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leal lret_target, %eax
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pushl %eax
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/* Enter paged protected Mode, activating Long Mode */
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movl $(X86_CR0_PG | X86_CR0_PE), %eax
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movl %eax, %cr0
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/* Jump from 32bit compatibility mode into 64bit mode. */
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lret
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code64:
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lret_target:
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pop %eax /* target */
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mov %eax, %eax /* Clear bits 63:32 */
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jmp *%eax /* Jump to the 64-bit target */
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.data
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.align 16
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.globl gdt64
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gdt64:
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gdt:
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.word gdt_end - gdt - 1
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.long gdt /* Fixed up by code above */
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.word 0
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.quad 0x0000000000000000 /* NULL descriptor */
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.quad 0x00af9a000000ffff /* __KERNEL_CS */
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.quad 0x00cf92000000ffff /* __KERNEL_DS */
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.quad 0x0080890000000000 /* TS descriptor */
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.quad 0x0000000000000000 /* TS continued */
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gdt_end:
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