mirror of
https://github.com/AsahiLinux/u-boot
synced 2025-03-13 21:36:57 +00:00
34bfe8eff8
On Arm platforms that use ACPI they cannot rely on the "spin-table" CPU bringup usually defined in the FDT. Thus implement the 'ACPI Multi-processor Startup for ARM Platforms', also referred to as 'ACPI parking protocol'. The ACPI parking protocol works similar to the spin-table mechanism, but the specification also covers lots of shortcomings of the spin-table implementations. Every CPU defined in the ACPI MADT table has it's own 4K page where the spinloop code and the OS mailbox resides. When selected the U-Boot board code must make sure that the secondary CPUs enter u-boot after relocation as well, so that they can enter the spinloop code residing in the ACPI parking protocol pages. The OS will then write to the mailbox and generate an IPI to release the CPUs from the spinloop code. For now it's only implemented on ARMv8, but can easily be extended to other platforms, like ARMv7. TEST: Boots all CPUs on qemu-system-aarch64 -machine raspi4b Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-by: Simon Glass <sjg@chromium.org> Cc: Simon Glass <sjg@chromium.org> Cc: Tom Rini <trini@konsulko.com> |
||
|---|---|---|
| .. | ||
| acpi_device.h | ||
| acpi_dp.h | ||
| acpi_s3.h | ||
| acpi_table.h | ||
| acpigen.h | ||