Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 42 insertions, 0 deletions

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