1ppce500 generic platform (``ppce500``) 2====================================== 3 4QEMU for PPC supports a special ``ppce500`` machine designed for emulation and 5virtualization purposes. 6 7Supported devices 8----------------- 9 10The ``ppce500`` machine supports the following devices: 11 12* PowerPC e500 series core (e500v2/e500mc/e5500/e6500) 13* Configuration, Control, and Status Register (CCSR) 14* Multicore Programmable Interrupt Controller (MPIC) with MSI support 15* 1 16550A UART device 16* 1 Freescale MPC8xxx I2C controller 17* 1 Pericom pt7c4338 RTC via I2C 18* 1 Freescale MPC8xxx GPIO controller 19* Power-off functionality via one GPIO pin 20* 1 Freescale MPC8xxx PCI host controller 21* VirtIO devices via PCI bus 22* 1 Freescale Enhanced Triple Speed Ethernet controller (eTSEC) 23 24Hardware configuration information 25---------------------------------- 26 27The ``ppce500`` machine automatically generates a device tree blob ("dtb") 28which it passes to the guest, if there is no ``-dtb`` option. This provides 29information about the addresses, interrupt lines and other configuration of 30the various devices in the system. 31 32If users want to provide their own DTB, they can use the ``-dtb`` option. 33These DTBs should have the following requirements: 34 35* The number of subnodes under /cpus node should match QEMU's ``-smp`` option 36* The /memory reg size should match QEMU’s selected ram_size via ``-m`` 37 38Both ``qemu-system-ppc`` and ``qemu-system-ppc64`` provide emulation for the 39following 32-bit PowerPC CPUs: 40 41* e500v2 42* e500mc 43 44Additionally ``qemu-system-ppc64`` provides support for the following 64-bit 45PowerPC CPUs: 46 47* e5500 48* e6500 49 50The CPU type can be specified via the ``-cpu`` command line. If not specified, 51it creates a machine with e500v2 core. The following example shows an e6500 52based machine creation: 53 54.. code-block:: bash 55 56 $ qemu-system-ppc64 -nographic -M ppce500 -cpu e6500 57 58Boot options 59------------ 60 61The ``ppce500`` machine can start using the standard -kernel functionality 62for loading a payload like an OS kernel (e.g.: Linux), or U-Boot firmware. 63 64When -bios is omitted, the default pc-bios/u-boot.e500 firmware image is used 65as the BIOS. QEMU follows below truth table to select which payload to execute: 66 67===== ========== ======= 68-bios -kernel payload 69===== ========== ======= 70 N N u-boot 71 N Y kernel 72 Y don't care u-boot 73===== ========== ======= 74 75When both -bios and -kernel are present, QEMU loads U-Boot and U-Boot in turns 76automatically loads the kernel image specified by the -kernel parameter via 77U-Boot's built-in "bootm" command, hence a legacy uImage format is required in 78such senario. 79 80Running Linux kernel 81-------------------- 82 83Linux mainline v5.11 release is tested at the time of writing. To build a 84Linux mainline kernel that can be booted by the ``ppce500`` machine in 8564-bit mode, simply configure the kernel using the defconfig configuration: 86 87.. code-block:: bash 88 89 $ export ARCH=powerpc 90 $ export CROSS_COMPILE=powerpc-linux- 91 $ make corenet64_smp_defconfig 92 $ make menuconfig 93 94then manually select the following configuration: 95 96 Platform support > Freescale Book-E Machine Type > QEMU generic e500 platform 97 98To boot the newly built Linux kernel in QEMU with the ``ppce500`` machine: 99 100.. code-block:: bash 101 102 $ qemu-system-ppc64 -M ppce500 -cpu e5500 -smp 4 -m 2G \ 103 -display none -serial stdio \ 104 -kernel vmlinux \ 105 -initrd /path/to/rootfs.cpio \ 106 -append "root=/dev/ram" 107 108To build a Linux mainline kernel that can be booted by the ``ppce500`` machine 109in 32-bit mode, use the same 64-bit configuration steps except the defconfig 110file should use corenet32_smp_defconfig. 111 112To boot the 32-bit Linux kernel: 113 114.. code-block:: bash 115 116 $ qemu-system-ppc{64|32} -M ppce500 -cpu e500mc -smp 4 -m 2G \ 117 -display none -serial stdio \ 118 -kernel vmlinux \ 119 -initrd /path/to/rootfs.cpio \ 120 -append "root=/dev/ram" 121 122Running U-Boot 123-------------- 124 125U-Boot mainline v2021.07 release is tested at the time of writing. To build a 126U-Boot mainline bootloader that can be booted by the ``ppce500`` machine, use 127the qemu-ppce500_defconfig with similar commands as described above for Linux: 128 129.. code-block:: bash 130 131 $ export CROSS_COMPILE=powerpc-linux- 132 $ make qemu-ppce500_defconfig 133 134You will get u-boot file in the build tree. 135 136When U-Boot boots, you will notice the following if using with ``-cpu e6500``: 137 138.. code-block:: none 139 140 CPU: Unknown, Version: 0.0, (0x00000000) 141 Core: e6500, Version: 2.0, (0x80400020) 142 143This is because we only specified a core name to QEMU and it does not have a 144meaningful SVR value which represents an actual SoC that integrates such core. 145You can specify a real world SoC device that QEMU has built-in support but all 146these SoCs are e500v2 based MPC85xx series, hence you cannot test anything 147built for P4080 (e500mc), P5020 (e5500) and T2080 (e6500). 148 149By default a VirtIO standard PCI networking device is connected as an ethernet 150interface at PCI address 0.1.0, but we can switch that to an e1000 NIC by: 151 152.. code-block:: bash 153 154 $ qemu-system-ppc -M ppce500 -smp 4 -m 2G \ 155 -display none -serial stdio \ 156 -bios u-boot \ 157 -nic tap,ifname=tap0,script=no,downscript=no,model=e1000 158 159The QEMU ``ppce500`` machine can also dynamically instantiate an eTSEC device 160if “-device eTSEC” is given to QEMU: 161 162.. code-block:: bash 163 164 -netdev tap,ifname=tap0,script=no,downscript=no,id=net0 -device eTSEC,netdev=net0 165