Update description to use the MIPS Malta board for Qemu.
Signed-off-by: Daniel Schwierzeck daniel.schwierzeck@gmail.com
---
doc/board/emulation/qemu-mips.rst | 273 +++++++++--------------------- 1 file changed, 78 insertions(+), 195 deletions(-)
diff --git a/doc/board/emulation/qemu-mips.rst b/doc/board/emulation/qemu-mips.rst index d35925126a..5fd8a0a23b 100644 --- a/doc/board/emulation/qemu-mips.rst +++ b/doc/board/emulation/qemu-mips.rst @@ -1,246 +1,129 @@ .. SPDX-License-Identifier: GPL-2.0+ -.. sectionauthor:: Vlad Lungu vlad.lungu@windriver.com +.. sectionauthor:: Daniel Schwierzeck daniel.schwierzeck@gmail.com
QEMU MIPS =========
-Qemu is a full system emulator. See http://www.nongnu.org/qemu/ +Qemu for MIPS is based on the MIPS Malta board. The built Malta U-Boot +images can be used for Qemu and on physical hardware. The Malta board +supports all combinations of Little and Big Endian as well as 32 bit +and 64 bit.
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 ----------------------------- +The memory size for Qemu is hard-coded to 256 MiB. For Malta Little Endian +targets an extra endianness swapped image named *u-boot-swap.bin* is +generated and required for Qemu.
Example usage -^^^^^^^^^^^^^ - -Using u-boot.bin as ROM (replaces Qemu monitor): +-------------
-32 bit, big endian +Build for 32 bit, big endian:
.. code-block:: bash
- make qemu_mips_defconfig - qemu-system-mips -M mips -bios u-boot.bin -nographic + make malta_defconfig + make + UBOOT_BIN=u-boot.bin + QEMU_BIN=qemu-system-mips + QEMU_CPU=24Kc
-32 bit, little endian +Build for 32 bit, little endian:
.. code-block:: bash
- make qemu_mipsel_defconfig - qemu-system-mipsel -M mips -bios u-boot.bin -nographic + make maltael_defconfig + make + UBOOT_BIN=u-boot-swap.bin + QEMU_BIN=qemu-system-mipsel + QEMU_CPU=24Kc
-64 bit, big endian +Build for 64 bit, big endian:
.. code-block:: bash
- make qemu_mips64_defconfig - qemu-system-mips64 -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic + make malta64_defconfig + make + UBOOT_BIN=u-boot.bin + QEMU_BIN=qemu-system-mips64 + QEMU_CPU=MIPS64R2-generic
-64 bit, little endian +Build for 64 bit, little endian:
.. code-block:: bash
- make qemu_mips64el_defconfig - qemu-system-mips64el -cpu MIPS64R2-generic -M mips -bios u-boot.bin -nographic + make malta64el_defconfig + make + UBOOT_BIN=u-boot-swap.bin + QEMU_BIN=qemu-system-mips64el + QEMU_CPU=MIPS64R2-generic
-or using u-boot.bin from emulated flash: - -if you use a QEMU version after commit 4224 +Generate NOR flash image with U-Boot binary:
.. 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:: + dd if=/dev/zero bs=1M count=4 | tr '\000' '\377' > pflash.img + dd if=${UBOOT_BIN} of=pflash.img conv=notrunc
- #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 -^^^^^^^^^^^^^^^^^^^^ +Start Qemu:
.. code-block:: bash
- dd if=uImage bs=1k conv=notrunc seek=224 of=flash - -Generate Ide Disk -^^^^^^^^^^^^^^^^^ + mkdir tftproot + ${QEMU_BIN} -nographic -cpu ${QEMU_CPU} -m 256 -drive if=pflash,file="$(pwd)/pflash.img",format=raw -netdev user,id=net0,tftp="$(pwd)/tftproot" -device pcnet,netdev=net0
.. code-block:: bash
- dd of=ide bs=1k count=100k if=/dev/zero + U-Boot 2021.04-00963-g60279a2b1d (Apr 21 2021 - 19:54:32 +0200)
- # 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 + Board: MIPS Malta CoreLV + DRAM: 256 MiB + Flash: 4 MiB + Loading Environment from Flash... *** Warning - bad CRC, using default environment
-Copy to ide -^^^^^^^^^^^ + In: serial@3f8 + Out: serial@3f8 + Err: serial@3f8 + Net: pcnet#0 + IDE: Bus 0: not available + maltael #
-.. code-block:: bash - - dd if=uImage bs=512 conv=notrunc seek=63 of=ide +How to debug U-Boot +-------------------
-Generate ext2 on part 2 on Copy uImage and initrd.gz -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +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). Start Qemu in the first console:
.. 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 + mkdir tftproot + ${QEMU_BIN} -s -S -nographic -cpu ${QEMU_CPU} -m 256 -drive if=pflash,file="$(pwd)/pflash.img",format=raw -netdev user,id=net0,tftp="$(pwd)/tftproot" -device pcnet,netdev=net0
- 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 +In the second console start gdb:
.. 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) + gdb-multiarch --eval-command "target remote :1234" u-boot
.. 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) + GNU gdb (Ubuntu 9.2-0ubuntu1~20.04) 9.2 + Copyright (C) 2020 Free Software Foundation, Inc. + License GPLv3+: GNU GPL version 3 or later http://gnu.org/licenses/gpl.html + This is free software: you are free to change and redistribute it. + There is NO WARRANTY, to the extent permitted by law. + Type "show copying" and "show warranty" for details. + This GDB was configured as "x86_64-linux-gnu". + Type "show configuration" for configuration details. + For bug reporting instructions, please see: + http://www.gnu.org/software/gdb/bugs/. + Find the GDB manual and other documentation resources online at: + http://www.gnu.org/software/gdb/documentation/. + + For help, type "help". + Type "apropos word" to search for commands related to "word"... + Reading symbols from u-boot... + Remote debugging using :1234 + 0xbfc00000 in ?? () + (gdb) c + Continuing.