mirror of
https://source.denx.de/u-boot/u-boot.git
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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>
131 lines
2.9 KiB
ArmAsm
131 lines
2.9 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* U-Boot - x86 Startup Code
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*
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* (C) Copyright 2008-2011
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* Graeme Russ, <graeme.russ@gmail.com>
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*
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* (C) Copyright 2002,2003
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* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
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*/
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#include <asm/global_data.h>
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#include <asm/processor-flags.h>
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#define BOOT_SEG 0xffff0000 /* linear segment of boot code */
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#define a32 .byte 0x67;
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#define o32 .byte 0x66;
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.section .start16, "ax"
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.code16
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.globl start16
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start16:
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/* Save BIST */
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movl %eax, %ecx
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/* Set the Cold Boot / Hard Reset flag */
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movl $GD_FLG_COLD_BOOT, %ebx
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xorl %eax, %eax
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movl %eax, %cr3 /* Invalidate TLB */
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/* Turn off cache (this might require a 486-class CPU) */
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movl %cr0, %eax
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orl $(X86_CR0_NW | X86_CR0_CD), %eax
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movl %eax, %cr0
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wbinvd
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/* load the temporary Global Descriptor Table */
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o32 cs lidt idt_ptr
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o32 cs lgdt gdt_ptr
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/* Now, we enter protected mode */
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movl %cr0, %eax
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orl $X86_CR0_PE, %eax
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movl %eax, %cr0
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/* Flush the prefetch queue */
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jmp ff
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ff:
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/* Finally restore BIST and jump to the 32-bit initialization code */
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movw $code32start, %ax
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movw %ax, %bp
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movl %ecx, %eax
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o32 cs ljmp *(%bp)
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/* 48-bit far pointer */
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code32start:
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.long _start /* offset */
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.word 0x10 /* segment */
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idt_ptr:
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.word 0 /* limit */
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.long 0 /* base */
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/*
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* The following Global Descriptor Table is just enough to get us into
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* 'Flat Protected Mode' - It will be discarded as soon as the final
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* GDT is setup in a safe location in RAM
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*/
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gdt_ptr:
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.word 0x1f /* limit (31 bytes = 4 GDT entries - 1) */
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.long BOOT_SEG + gdt_rom /* base */
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/* Some CPUs are picky about GDT alignment... */
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.align 16
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.globl gdt_rom
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gdt_rom:
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/*
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* The GDT table ...
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*
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* Selector Type
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* 0x00 NULL
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* 0x08 Unused
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* 0x10 32bit code
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* 0x18 32bit data/stack
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*/
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/* The NULL Desciptor - Mandatory */
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.word 0x0000 /* limit_low */
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.word 0x0000 /* base_low */
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.byte 0x00 /* base_middle */
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.byte 0x00 /* access */
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.byte 0x00 /* flags + limit_high */
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.byte 0x00 /* base_high */
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/* Unused Desciptor - (matches Linux) */
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.word 0x0000 /* limit_low */
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.word 0x0000 /* base_low */
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.byte 0x00 /* base_middle */
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.byte 0x00 /* access */
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.byte 0x00 /* flags + limit_high */
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.byte 0x00 /* base_high */
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/*
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* The Code Segment Descriptor:
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* - Base = 0x00000000
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* - Size = 4GB
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* - Access = Present, Ring 0, Exec (Code), Readable
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* - Flags = 4kB Granularity, 32-bit
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*/
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.word 0xffff /* limit_low */
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.word 0x0000 /* base_low */
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.byte 0x00 /* base_middle */
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.byte 0x9b /* access */
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.byte 0xcf /* flags + limit_high */
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.byte 0x00 /* base_high */
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/*
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* The Data Segment Descriptor:
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* - Base = 0x00000000
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* - Size = 4GB
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* - Access = Present, Ring 0, Non-Exec (Data), Writable
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* - Flags = 4kB Granularity, 32-bit
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*/
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.word 0xffff /* limit_low */
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.word 0x0000 /* base_low */
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.byte 0x00 /* base_middle */
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.byte 0x93 /* access */
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.byte 0xcf /* flags + limit_high */
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.byte 0x00 /* base_high */
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