Change Note 2025-08-02

Kernel-v3 API changes; new kernel-v3t variant.

Kernel-v3

• Various API changes to the kernel modules.
• Each module implementing shared data (such as queues) now handles protection for each procedure call. Before, some protection was provided by the kernel procedures.
• Move functionality to run the ready queue to the kernel module.

Kernel-v3t

• While kernel-v3 disables interrupts to protect shared data, a new variant kernel-v3t uses a [trap handler]({{< relref "/concepts/architecture/kernel-traps" >}}) for the same purpose.
• A new module SysCall implements the trap functionality.
• Otherwise unchanged to kernel-v3.

Status

• Both kernel-v3 variants are experimental.
• See [Description]({{< relref "/docs/lib/kernel-v3/kernel-v3-desc" >}}).

Config Files

• Add kernel-v3t config for Pico2.

Example Programs

• K3base: basic test program for kernel-v3.
• K3tbase: same basic test program for kernel-v3t.

Last updated: 2 August 2025