Platforms

A platform is a build target for the kernel. In some cases, there is only one platform for an entire architecture because the hardware is relatively standardized (e.g. x86_64). Other times, hardware is different enough between platforms that it's easier to treat them as different targets (e.g. a headless ARM server that boots using UEFI, versus a Raspberry Pi).

All supported platforms are enumerated in the table below - some have their own sections with more details, while others are just described below. The platform you want to build for is specified in your Poplar.toml configuration file, or with the -p/--platform flag to xtask. Some platforms also have custom xtask commands to, for example, flash a device with a built image.

Platform: x64

The vast majority of x86_64 hardware is pretty similar, and so is treated as a single platform. It uses the hal_x86_64 HAL. We assume that the platform:

• Boots using UEFI (using seed_uefi)
• Supports the APIC
• Supports the xsave instruction

Platform: rv64_virt

This is a virtual RISC-V platform emulated by qemu-system-riscv64's virt machine. It features:

• A customizable number of emulated RV64 HARTs
• Is booted via QEMU's -kernel option and OpenSBI
• A Virtio block device with attached GPT 'disk'
• Support for USB devices via EHCI

Devices such as the EHCI USB controller are connected to a PCIe bus, and so we use the Advanced Interrupt Architecture with MSIs to avoid the complexity of shared pin-based PCI interrupts. This is done by passing the aia=aplic-imsic machine option to QEMU.