Module user_context

Expand description

Runtime gating for user-mode FPU / Vector context handling.

This module complements Cargo feature gates (user-fpu, user-vector) with a DTB(FDT)-driven runtime switch. When the relevant Cargo feature is enabled, the kernel will decide at boot whether user-mode access should actually be allowed based on information found in the device tree.

§DTB overrides

If present under /chosen, the following properties override auto-detection:

scarlet,user-fpu (boolean or u32/u64)
scarlet,user-vector (boolean or u32/u64)

When absent, the kernel attempts architecture-specific detection when available (currently implemented for RISC-V via riscv,isa).

Constants§

FLAG_USER_FPU 🔒
FLAG_USER_VECTOR 🔒

Statics§

FLAGS 🔒
INITIALIZED 🔒

Functions§

arch_defaults_from_fdt 🔒
bytes_to_cstr 🔒
init_from_fdt: Initialize runtime user-context switches from the current DTB (FDT).
read_boolish_property 🔒
riscv_extensions_from_fdt 🔒
riscv_extensions_from_isa_extensions 🔒
riscv_extensions_from_isa_string 🔒
riscv_isa_suffix_has_vector_tokens 🔒
riscv_token_is_fpu 🔒
riscv_token_is_vector 🔒
user_fpu_enabled: Returns whether user-mode FPU context handling is enabled (feature + DTB).
user_vector_enabled: Returns whether user-mode Vector context handling is enabled (feature + DTB).