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Diffstat (limited to 'doc/board/emulation')
| -rw-r--r-- | doc/board/emulation/index.rst | 1 | ||||
| -rw-r--r-- | doc/board/emulation/qemu-mips.rst | 234 |
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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) |