| 1 | ppce500 generic platform (``ppce500``) |
| 2 | ====================================== |
| 3 | |
| 4 | QEMU for PPC supports a special ``ppce500`` machine designed for emulation and |
| 5 | virtualization purposes. |
| 6 | |
| 7 | Supported devices |
| 8 | ----------------- |
| 9 | |
| 10 | The ``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 Secure Digital Host controller (eSDHC) |
| 23 | * 1 Freescale Enhanced Triple Speed Ethernet controller (eTSEC) |
| 24 | |
| 25 | Hardware configuration information |
| 26 | ---------------------------------- |
| 27 | |
| 28 | The ``ppce500`` machine automatically generates a device tree blob ("dtb") |
| 29 | which it passes to the guest, if there is no ``-dtb`` option. This provides |
| 30 | information about the addresses, interrupt lines and other configuration of |
| 31 | the various devices in the system. |
| 32 | |
| 33 | If users want to provide their own DTB, they can use the ``-dtb`` option. |
| 34 | These DTBs should have the following requirements: |
| 35 | |
| 36 | * The number of subnodes under /cpus node should match QEMU's ``-smp`` option |
| 37 | * The /memory reg size should match QEMU’s selected ram_size via ``-m`` |
| 38 | |
| 39 | Both ``qemu-system-ppc`` and ``qemu-system-ppc64`` provide emulation for the |
| 40 | following 32-bit PowerPC CPUs: |
| 41 | |
| 42 | * e500v2 |
| 43 | * e500mc |
| 44 | |
| 45 | Additionally ``qemu-system-ppc64`` provides support for the following 64-bit |
| 46 | PowerPC CPUs: |
| 47 | |
| 48 | * e5500 |
| 49 | * e6500 |
| 50 | |
| 51 | The CPU type can be specified via the ``-cpu`` command line. If not specified, |
| 52 | it creates a machine with e500v2 core. The following example shows an e6500 |
| 53 | based machine creation: |
| 54 | |
| 55 | .. code-block:: bash |
| 56 | |
| 57 | $ qemu-system-ppc64 -nographic -M ppce500 -cpu e6500 |
| 58 | |
| 59 | Boot options |
| 60 | ------------ |
| 61 | |
| 62 | The ``ppce500`` machine can start using the standard -kernel functionality |
| 63 | for loading a payload like an OS kernel (e.g.: Linux), or U-Boot firmware. |
| 64 | |
| 65 | When -bios is omitted, the default pc-bios/u-boot.e500 firmware image is used |
| 66 | as the BIOS. QEMU follows below truth table to select which payload to execute: |
| 67 | |
| 68 | ===== ========== ======= |
| 69 | -bios -kernel payload |
| 70 | ===== ========== ======= |
| 71 | N N u-boot |
| 72 | N Y kernel |
| 73 | Y don't care u-boot |
| 74 | ===== ========== ======= |
| 75 | |
| 76 | When both -bios and -kernel are present, QEMU loads U-Boot and U-Boot in turns |
| 77 | automatically loads the kernel image specified by the -kernel parameter via |
| 78 | U-Boot's built-in "bootm" command, hence a legacy uImage format is required in |
| 79 | such scenario. |
| 80 | |
| 81 | Running Linux kernel |
| 82 | -------------------- |
| 83 | |
| 84 | Linux mainline v5.11 release is tested at the time of writing. To build a |
| 85 | Linux mainline kernel that can be booted by the ``ppce500`` machine in |
| 86 | 64-bit mode, simply configure the kernel using the defconfig configuration: |
| 87 | |
| 88 | .. code-block:: bash |
| 89 | |
| 90 | $ export ARCH=powerpc |
| 91 | $ export CROSS_COMPILE=powerpc-linux- |
| 92 | $ make corenet64_smp_defconfig |
| 93 | $ make menuconfig |
| 94 | |
| 95 | then manually select the following configuration: |
| 96 | |
| 97 | Platform support > Freescale Book-E Machine Type > QEMU generic e500 platform |
| 98 | |
| 99 | To boot the newly built Linux kernel in QEMU with the ``ppce500`` machine: |
| 100 | |
| 101 | .. code-block:: bash |
| 102 | |
| 103 | $ qemu-system-ppc64 -M ppce500 -cpu e5500 -smp 4 -m 2G \ |
| 104 | -display none -serial stdio \ |
| 105 | -kernel vmlinux \ |
| 106 | -initrd /path/to/rootfs.cpio \ |
| 107 | -append "root=/dev/ram" |
| 108 | |
| 109 | To build a Linux mainline kernel that can be booted by the ``ppce500`` machine |
| 110 | in 32-bit mode, use the same 64-bit configuration steps except the defconfig |
| 111 | file should use corenet32_smp_defconfig. |
| 112 | |
| 113 | To boot the 32-bit Linux kernel: |
| 114 | |
| 115 | .. code-block:: bash |
| 116 | |
| 117 | $ qemu-system-ppc64 -M ppce500 -cpu e500mc -smp 4 -m 2G \ |
| 118 | -display none -serial stdio \ |
| 119 | -kernel vmlinux \ |
| 120 | -initrd /path/to/rootfs.cpio \ |
| 121 | -append "root=/dev/ram" |
| 122 | |
| 123 | Running U-Boot |
| 124 | -------------- |
| 125 | |
| 126 | U-Boot mainline v2021.07 release is tested at the time of writing. To build a |
| 127 | U-Boot mainline bootloader that can be booted by the ``ppce500`` machine, use |
| 128 | the qemu-ppce500_defconfig with similar commands as described above for Linux: |
| 129 | |
| 130 | .. code-block:: bash |
| 131 | |
| 132 | $ export CROSS_COMPILE=powerpc-linux- |
| 133 | $ make qemu-ppce500_defconfig |
| 134 | |
| 135 | You will get u-boot file in the build tree. |
| 136 | |
| 137 | When U-Boot boots, you will notice the following if using with ``-cpu e6500``: |
| 138 | |
| 139 | .. code-block:: none |
| 140 | |
| 141 | CPU: Unknown, Version: 0.0, (0x00000000) |
| 142 | Core: e6500, Version: 2.0, (0x80400020) |
| 143 | |
| 144 | This is because we only specified a core name to QEMU and it does not have a |
| 145 | meaningful SVR value which represents an actual SoC that integrates such core. |
| 146 | You can specify a real world SoC device that QEMU has built-in support but all |
| 147 | these SoCs are e500v2 based MPC85xx series, hence you cannot test anything |
| 148 | built for P4080 (e500mc), P5020 (e5500) and T2080 (e6500). |
| 149 | |
| 150 | Networking |
| 151 | ---------- |
| 152 | |
| 153 | By default a VirtIO standard PCI networking device is connected as an ethernet |
| 154 | interface at PCI address 0.1.0, but we can switch that to an e1000 NIC by: |
| 155 | |
| 156 | .. code-block:: bash |
| 157 | |
| 158 | $ qemu-system-ppc64 -M ppce500 -smp 4 -m 2G \ |
| 159 | -display none -serial stdio \ |
| 160 | -bios u-boot \ |
| 161 | -nic tap,ifname=tap0,script=no,downscript=no,model=e1000 |
| 162 | |
| 163 | The QEMU ``ppce500`` machine can also dynamically instantiate an eTSEC device |
| 164 | if “-device eTSEC” is given to QEMU: |
| 165 | |
| 166 | .. code-block:: bash |
| 167 | |
| 168 | -netdev tap,ifname=tap0,script=no,downscript=no,id=net0 -device eTSEC,netdev=net0 |
| 169 | |
| 170 | Root file system on flash drive |
| 171 | ------------------------------- |
| 172 | |
| 173 | Rather than using a root file system on ram disk, it is possible to have it on |
| 174 | CFI flash. Given an ext2 image whose size must be a power of two, it can be used |
| 175 | as follows: |
| 176 | |
| 177 | .. code-block:: bash |
| 178 | |
| 179 | $ qemu-system-ppc64 -M ppce500 -cpu e500mc -smp 4 -m 2G \ |
| 180 | -display none -serial stdio \ |
| 181 | -kernel vmlinux \ |
| 182 | -drive if=pflash,file=/path/to/rootfs.ext2,format=raw \ |
| 183 | -append "rootwait root=/dev/mtdblock0" |
| 184 | |
| 185 | Alternatively, the root file system can also reside on an emulated SD card |
| 186 | whose size must again be a power of two: |
| 187 | |
| 188 | .. code-block:: bash |
| 189 | |
| 190 | $ qemu-system-ppc64 -M ppce500 -cpu e500mc -smp 4 -m 2G \ |
| 191 | -display none -serial stdio \ |
| 192 | -kernel vmlinux \ |
| 193 | -device sd-card,drive=mydrive \ |
| 194 | -drive id=mydrive,if=none,file=/path/to/rootfs.ext2,format=raw \ |
| 195 | -append "rootwait root=/dev/mmcblk0" |