doc: board: Convert README.qemu-mips to reST

Convert plain text documentation to reStructuredText format and add
it to Sphinx TOC tree. No essential content change.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

2 files changed, 235 insertions, 0 deletions

diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst
index 7537179e2fb..1adefee1552 100644
--- a/doc/board/emulation/index.rst
+++ b/doc/board/emulation/index.rst
@@ -7,5 +7,6 @@ Emulation
    :maxdepth: 2
 
    qemu-arm
+   qemu-mips
    qemu-riscv
    qemu-x86
diff --git a/doc/board/emulation/qemu-mips.rst b/doc/board/emulation/qemu-mips.rst
new file mode 100644
index 00000000000..529a908b55b
--- /dev/null
+++ b/doc/board/emulation/qemu-mips.rst
@@ -0,0 +1,234 @@
+.. SPDX-License-Identifier: GPL-2.0+
+.. sectionauthor:: Vlad Lungu <vlad.lungu@windriver.com>
+
+QEMU MIPS
+=========
+
+Qemu is a full system emulator. See http://www.nongnu.org/qemu/
+
+Limitations & comments
+----------------------
+Supports the "-M mips" configuration of qemu: serial,NE2000,IDE.
+Supports little and big endian as well as 32 bit and 64 bit.
+Derived from au1x00 with a lot of things cut out.
+
+Supports emulated flash (patch Jean-Christophe PLAGNIOL-VILLARD) with
+recent qemu versions. When using emulated flash, launch with
+-pflash <filename> and erase mips_bios.bin.
+
+
+Notes for the Qemu MIPS port
+----------------------------
+
+Example usage
+^^^^^^^^^^^^^
+
+Using u-boot.bin as ROM (replaces Qemu monitor):
+
+32 bit, big endian::
+
+   # make qemu_mips
+   # qemu-system-mips -M mips -bios u-boot.bin -nographic
+
+32 bit, little endian::
+
+   # make qemu_mipsel
+   # qemu-system-mipsel -M mips -bios u-boot.bin -nographic
+
+64 bit, big endian::
+
+   # make qemu_mips64
+   # qemu-system-mips64 -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic
+
+64 bit, little endian::
+
+   # make qemu_mips64el
+   # qemu-system-mips64el -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic
+
+or using u-boot.bin from emulated flash:
+
+if you use a qemu version after commit 4224
+
+.. code-block:: none
+
+   create image:
+   # dd of=flash bs=1k count=4k if=/dev/zero
+   # dd of=flash bs=1k conv=notrunc if=u-boot.bin
+   start it (see above):
+   # qemu-system-mips[64][el] [-cpu MIPS64R2-generic] -M mips -pflash flash -nographic
+
+Download kernel + initrd
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+On ftp://ftp.denx.de/pub/contrib/Jean-Christophe_Plagniol-Villard/qemu_mips/
+you can downland::
+
+   #config to build the kernel
+   qemu_mips_defconfig
+   #patch to fix mips interrupt init on 2.6.24.y kernel
+   qemu_mips_kernel.patch
+   initrd.gz
+   vmlinux
+   vmlinux.bin
+   System.map
+
+Generate uImage
+^^^^^^^^^^^^^^^
+
+.. code-block:: none
+
+   # tools/mkimage -A mips -O linux -T kernel -C gzip -a 0x80010000 -e 0x80245650 -n "Linux 2.6.24.y" -d vmlinux.bin.gz uImage
+
+Copy uImage to Flash
+^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: none
+
+   # dd if=uImage bs=1k conv=notrunc seek=224 of=flash
+
+Generate Ide Disk
+^^^^^^^^^^^^^^^^^
+
+.. code-block:: none
+
+   # dd of=ide bs=1k cout=100k if=/dev/zero
+
+   # sfdisk -C 261 -d ide
+   # partition table of ide
+   unit: sectors
+
+        ide1 : start=       63, size=    32067, Id=83
+        ide2 : start=    32130, size=    32130, Id=83
+        ide3 : start=    64260, size=  4128705, Id=83
+        ide4 : start=        0, size=        0, Id= 0
+
+Copy to ide
+^^^^^^^^^^^
+
+.. code-block:: none
+
+   # dd if=uImage bs=512 conv=notrunc seek=63 of=ide
+
+Generate ext2 on part 2 on Copy uImage and initrd.gz
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: none
+
+   # Attached as loop device ide offset = 32130 * 512
+   # losetup -o 16450560 -f ide
+   # Format as ext2 ( arg2 : nb blocks)
+   # mke2fs /dev/loop0 16065
+   # losetup -d /dev/loop0
+   # Mount and copy uImage and initrd.gz to it
+   # mount -o loop,offset=16450560 -t ext2 ide /mnt
+   # mkdir /mnt/boot
+   # cp {initrd.gz,uImage} /mnt/boot/
+   # Umount it
+   # umount /mnt
+
+Set Environment
+^^^^^^^^^^^^^^^
+
+.. code-block:: none
+
+   setenv rd_start 0x80800000
+   setenv rd_size 2663940
+   setenv kernel BFC38000
+   setenv oad_addr 80500000
+   setenv load_addr2 80F00000
+   setenv kernel_flash BFC38000
+   setenv load_addr_hello 80200000
+   setenv bootargs 'root=/dev/ram0 init=/bin/sh'
+   setenv load_rd_ext2 'ide res; ext2load ide 0:2 ${rd_start} /boot/initrd.gz'
+   setenv load_rd_tftp 'tftp ${rd_start} /initrd.gz'
+   setenv load_kernel_hda 'ide res; diskboot ${load_addr} 0:2'
+   setenv load_kernel_ext2 'ide res; ext2load ide 0:2 ${load_addr} /boot/uImage'
+   setenv load_kernel_tftp 'tftp ${load_addr} /qemu_mips/uImage'
+   setenv boot_ext2_ext2 'run load_rd_ext2; run load_kernel_ext2; run addmisc; bootm ${load_addr}'
+   setenv boot_ext2_flash 'run load_rd_ext2; run addmisc; bootm ${kernel_flash}'
+   setenv boot_ext2_hda 'run load_rd_ext2; run load_kernel_hda; run addmisc; bootm ${load_addr}'
+   setenv boot_ext2_tftp 'run load_rd_ext2; run load_kernel_tftp; run addmisc; bootm ${load_addr}'
+   setenv boot_tftp_hda 'run load_rd_tftp; run load_kernel_hda; run addmisc; bootm ${load_addr}'
+   setenv boot_tftp_ext2 'run load_rd_tftp; run load_kernel_ext2; run addmisc; bootm ${load_addr}'
+   setenv boot_tftp_flash 'run load_rd_tftp; run addmisc; bootm ${kernel_flash}'
+   setenv boot_tftp_tftp 'run load_rd_tftp; run load_kernel_tftp; run addmisc; bootm ${load_addr}'
+   setenv load_hello_tftp 'tftp ${load_addr_hello} /examples/hello_world.bin'
+   setenv go_tftp 'run load_hello_tftp; go ${load_addr_hello}'
+   setenv addmisc 'setenv bootargs ${bootargs} console=ttyS0,${baudrate} rd_start=${rd_start} rd_size=${rd_size} ethaddr=${ethaddr}'
+   setenv bootcmd 'run boot_tftp_flash'
+
+Now you can boot from flash, ide, ide+ext2 and tfp::
+
+   # qemu-system-mips -M mips -pflash flash -monitor null -nographic -net nic -net user -tftp `pwd` -hda ide
+
+
+How to debug U-Boot
+-------------------
+
+In order to debug U-Boot you need to start qemu with gdb server support (-s)
+and waiting the connection to start the CPU (-S)
+
+.. code-block:: none
+
+   # qemu-system-mips -S -s -M mips -pflash flash -monitor null -nographic -net nic -net user -tftp `pwd` -hda ide
+
+in an other console you start gdb
+
+Debugging of U-Boot Before Relocation
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Before relocation, the addresses in the ELF file can be used without any problems
+by connecting to the gdb server localhost:1234
+
+.. code-block:: none
+
+   # mipsel-unknown-linux-gnu-gdb u-boot
+   GNU gdb 6.6
+   Copyright (C) 2006 Free Software Foundation, Inc.
+   GDB is free software, covered by the GNU General Public License, and you are
+   welcome to change it and/or distribute copies of it under certain conditions.
+   Type "show copying" to see the conditions.
+   There is absolutely no warranty for GDB.  Type "show warranty" for details.
+   This GDB was configured as "--host=i486-linux-gnu --target=mipsel-unknown-linux-gnu"...
+   (gdb)  target remote localhost:1234
+   Remote debugging using localhost:1234
+   _start () at start.S:64
+   64		RVECENT(reset,0)	/* U-Boot entry point */
+   Current language:  auto; currently asm
+   (gdb)  b board.c:289
+   Breakpoint 1 at 0xbfc00cc8: file board.c, line 289.
+   (gdb) c
+   Continuing.
+
+   Breakpoint 1, board_init_f (bootflag=<value optimized out>) at board.c:290
+   290		relocate_code (addr_sp, id, addr);
+   Current language:  auto; currently c
+   (gdb) p/x addr
+   $1 = 0x87fa0000
+
+Debugging of U-Boot After Relocation
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+For debugging U-Boot after relocation we need to know the address to which
+U-Boot relocates itself to 0x87fa0000 by default.
+And replace the symbol table to this offset.
+
+.. code-block:: none
+
+   (gdb) symbol-file
+   Discard symbol table from `/private/u-boot-arm/u-boot'? (y or n) y
+   Error in re-setting breakpoint 1:
+   No symbol table is loaded.  Use the "file" command.
+   No symbol file now.
+   (gdb) add-symbol-file u-boot 0x87fa0000
+   add symbol table from file "u-boot" at
+   	.text_addr = 0x87fa0000
+   (y or n) y
+   Reading symbols from /private/u-boot-arm/u-boot...done.
+   Breakpoint 1 at 0x87fa0cc8: file board.c, line 289.
+   (gdb) c
+   Continuing.
+
+   Program received signal SIGINT, Interrupt.
+   0xffffffff87fa0de4 in udelay (usec=<value optimized out>) at time.c:78
+   78		while ((tmo - read_c0_count()) < 0x7fffffff)