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1.. SPDX-License-Identifier: GPL-2.02 3=======================4Booting Linux/LoongArch5=======================6 7:Author: Yanteng Si <siyanteng@loongson.cn>8:Date: 18 Nov 20229 10Information passed from BootLoader to kernel11============================================12 13LoongArch supports ACPI and FDT. The information that needs to be passed14to the kernel includes the memmap, the initrd, the command line, optionally15the ACPI/FDT tables, and so on.16 17The kernel is passed the following arguments on `kernel_entry` :18 19 - a0 = efi_boot: `efi_boot` is a flag indicating whether20 this boot environment is fully UEFI-compliant.21 22 - a1 = cmdline: `cmdline` is a pointer to the kernel command line.23 24 - a2 = systemtable: `systemtable` points to the EFI system table.25 All pointers involved at this stage are in physical addresses.26 27Header of Linux/LoongArch kernel images28=======================================29 30Linux/LoongArch kernel images are EFI images. Being PE files, they have31a 64-byte header structured like::32 33 u32 MZ_MAGIC /* "MZ", MS-DOS header */34 u32 res0 = 0 /* Reserved */35 u64 kernel_entry /* Kernel entry point */36 u64 _end - _text /* Kernel image effective size */37 u64 load_offset /* Kernel image load offset from start of RAM */38 u64 res1 = 0 /* Reserved */39 u64 res2 = 0 /* Reserved */40 u64 res3 = 0 /* Reserved */41 u32 LINUX_PE_MAGIC /* Magic number */42 u32 pe_header - _head /* Offset to the PE header */43