1Arm Versatile Express boards (``vexpress-a9``, ``vexpress-a15``) 2================================================================ 3 4QEMU models two variants of the Arm Versatile Express development 5board family: 6 7- ``vexpress-a9`` models the combination of the Versatile Express 8 motherboard and the CoreTile Express A9x4 daughterboard 9- ``vexpress-a15`` models the combination of the Versatile Express 10 motherboard and the CoreTile Express A15x2 daughterboard 11 12Note that as this hardware does not have PCI, IDE or SCSI, 13the only available storage option is emulated SD card. 14 15Implemented devices: 16 17- PL041 audio 18- PL181 SD controller 19- PL050 keyboard and mouse 20- PL011 UARTs 21- SP804 timers 22- I2C controller 23- PL031 RTC 24- PL111 LCD display controller 25- Flash memory 26- LAN9118 ethernet 27 28Unimplemented devices: 29 30- SP810 system control block 31- PCI-express 32- USB controller (Philips ISP1761) 33- Local DAP ROM 34- CoreSight interfaces 35- PL301 AXI interconnect 36- SCC 37- System counter 38- HDLCD controller (``vexpress-a15``) 39- SP805 watchdog 40- PL341 dynamic memory controller 41- DMA330 DMA controller 42- PL354 static memory controller 43- BP147 TrustZone Protection Controller 44- TrustZone Address Space Controller 45 46Other differences between the hardware and the QEMU model: 47 48- QEMU will default to creating one CPU unless you pass a different 49 ``-smp`` argument 50- QEMU allows the amount of RAM provided to be specified with the 51 ``-m`` argument 52- QEMU defaults to providing a CPU which does not provide either 53 TrustZone or the Virtualization Extensions: if you want these you 54 must enable them with ``-machine secure=on`` and ``-machine 55 virtualization=on`` 56- QEMU provides 4 virtio-mmio virtio transports; these start at 57 address ``0x10013000`` for ``vexpress-a9`` and at ``0x1c130000`` for 58 ``vexpress-a15``, and have IRQs from 40 upwards. If a dtb is 59 provided on the command line then QEMU will edit it to include 60 suitable entries describing these transports for the guest. 61- QEMU does not currently support either dynamic or static remapping 62 of the area of memory at address 0: it is always mapped to alias 63 the first flash bank 64 65Booting a Linux kernel 66---------------------- 67 68Building a current Linux kernel with ``multi_v7_defconfig`` should be 69enough to get something running. Nowadays an out-of-tree build is 70recommended (and also useful if you build a lot of different targets). 71In the following example $BLD points to the build directory and $SRC 72points to the root of the Linux source tree. You can drop $SRC if you 73are running from there. 74 75.. code-block:: bash 76 77 $ make O=$BLD -C $SRC ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- multi_v7_defconfig 78 $ make O=$BLD -C $SRC ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- 79 80By default you will want to boot your rootfs off the sdcard interface. 81Your rootfs will need to be padded to the right size. With a suitable 82DTB you could also add devices to the virtio-mmio bus. 83 84.. code-block:: bash 85 86 $ qemu-system-arm -cpu cortex-a15 -smp 4 -m 4096 \ 87 -machine type=vexpress-a15 -serial mon:stdio \ 88 -drive if=sd,driver=file,filename=armel-rootfs.ext4 \ 89 -kernel zImage \ 90 -dtb vexpress-v2p-ca15-tc1.dtb \ 91 -append "console=ttyAMA0 root=/dev/mmcblk0 ro" 92