doc/board/emulation/qemu-mips.rst - filogic/uboot - Gitiles

 .. 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

 .. code-block:: bash

    make qemu_mips
    qemu-system-mips -M mips -bios u-boot.bin -nographic

 32 bit, little endian

 .. code-block:: bash

    make qemu_mipsel
    qemu-system-mipsel -M mips -bios u-boot.bin -nographic

 64 bit, big endian

 .. code-block:: bash

    make qemu_mips64
    qemu-system-mips64 -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic

 64 bit, little endian

 .. code-block:: bash

    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:: bash

    # 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:: bash

    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:: bash

    dd if=uImage bs=1k conv=notrunc seek=224 of=flash

 Generate Ide Disk
 ^^^^^^^^^^^^^^^^^

 .. code-block:: bash

    dd of=ide bs=1k count=100k if=/dev/zero

    # Create partion table
    sudo sfdisk ide << EOF
    label: dos
    label-id: 0x6fe3a999
    device: image
    unit: sectors
    image1 : start=       63, size=    32067, Id=83
    image2 : start=    32130, size=    32130, Id=83
    image3 : start=    64260, size=  4128705, Id=83
    EOF

 Copy to ide
 ^^^^^^^^^^^

 .. code-block:: bash

    dd if=uImage bs=512 conv=notrunc seek=63 of=ide

 Generate ext2 on part 2 on Copy uImage and initrd.gz
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 .. code-block:: bash

    # Attached as loop device ide offset = 32130 * 512
    sudo losetup -o 16450560 /dev/loop0 ide
    # Format as ext2 ( arg2 : nb blocks)
    sudo mkfs.ext2 /dev/loop0 16065
    sudo losetup -d /dev/loop0
    # Mount and copy uImage and initrd.gz to it
    sudo mount -o loop,offset=16450560 -t ext2 ide /mnt
    sudo mkdir /mnt/boot
    cp {initrd.gz,uImage} /mnt/boot/
    # Umount it
    sudo umount /mnt

 Set Environment
 ^^^^^^^^^^^^^^^

 .. code-block:: bash

    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

 .. code-block:: bash

    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:: bash

    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)
	.. 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

	.. code-block:: bash

	make qemu_mips
	qemu-system-mips -M mips -bios u-boot.bin -nographic

	32 bit, little endian

	.. code-block:: bash

	make qemu_mipsel
	qemu-system-mipsel -M mips -bios u-boot.bin -nographic

	64 bit, big endian

	.. code-block:: bash

	make qemu_mips64
	qemu-system-mips64 -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic

	64 bit, little endian

	.. code-block:: bash

	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:: bash

	# 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:: bash

	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:: bash

	dd if=uImage bs=1k conv=notrunc seek=224 of=flash

	Generate Ide Disk
	^^^^^^^^^^^^^^^^^

	.. code-block:: bash

	dd of=ide bs=1k count=100k if=/dev/zero

	# Create partion table
	sudo sfdisk ide << EOF
	label: dos
	label-id: 0x6fe3a999
	device: image
	unit: sectors
	image1 : start= 63, size= 32067, Id=83
	image2 : start= 32130, size= 32130, Id=83
	image3 : start= 64260, size= 4128705, Id=83
	EOF

	Copy to ide
	^^^^^^^^^^^

	.. code-block:: bash

	dd if=uImage bs=512 conv=notrunc seek=63 of=ide

	Generate ext2 on part 2 on Copy uImage and initrd.gz
	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

	.. code-block:: bash

	# Attached as loop device ide offset = 32130 * 512
	sudo losetup -o 16450560 /dev/loop0 ide
	# Format as ext2 ( arg2 : nb blocks)
	sudo mkfs.ext2 /dev/loop0 16065
	sudo losetup -d /dev/loop0
	# Mount and copy uImage and initrd.gz to it
	sudo mount -o loop,offset=16450560 -t ext2 ide /mnt
	sudo mkdir /mnt/boot
	cp {initrd.gz,uImage} /mnt/boot/
	# Umount it
	sudo umount /mnt

	Set Environment
	^^^^^^^^^^^^^^^

	.. code-block:: bash

	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

	.. code-block:: bash

	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:: bash

	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)