43 lines
1.5 KiB
ReStructuredText
43 lines
1.5 KiB
ReStructuredText
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.. SPDX-License-Identifier: GPL-2.0
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=======================
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Booting Linux/LoongArch
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=======================
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:Author: Yanteng Si <siyanteng@loongson.cn>
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:Date: 18 Nov 2022
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Information passed from BootLoader to kernel
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============================================
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LoongArch supports ACPI and FDT. The information that needs to be passed
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to the kernel includes the memmap, the initrd, the command line, optionally
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the ACPI/FDT tables, and so on.
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The kernel is passed the following arguments on `kernel_entry` :
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- a0 = efi_boot: `efi_boot` is a flag indicating whether
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this boot environment is fully UEFI-compliant.
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- a1 = cmdline: `cmdline` is a pointer to the kernel command line.
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- a2 = systemtable: `systemtable` points to the EFI system table.
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All pointers involved at this stage are in physical addresses.
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Header of Linux/LoongArch kernel images
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=======================================
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Linux/LoongArch kernel images are EFI images. Being PE files, they have
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a 64-byte header structured like::
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u32 MZ_MAGIC /* "MZ", MS-DOS header */
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u32 res0 = 0 /* Reserved */
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u64 kernel_entry /* Kernel entry point */
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u64 _end - _text /* Kernel image effective size */
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u64 load_offset /* Kernel image load offset from start of RAM */
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u64 res1 = 0 /* Reserved */
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u64 res2 = 0 /* Reserved */
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u64 res3 = 0 /* Reserved */
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u32 LINUX_PE_MAGIC /* Magic number */
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u32 pe_header - _head /* Offset to the PE header */
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