MontaukOS binaries could not use thread-local storage: the ELF loader
ignored PT_TLS and no FS base was ever programmed, so any %fs access
(initial-exec/local-exec TLS, e.g. libbfd's _Thread_local error state)
page faulted at address 0. This is the kernel prerequisite for
cc1plus/libstdc++ in the GCC port.
ELF loader: parse PT_TLS and build the main thread's TLS block above
the loaded image (x86-64 variant II ABI: block below the thread
pointer, TP = base + align_up(memsz, align), .tdata copied from the
template, .tbss zeroed, ABI self-pointer stored at [TP]). The
template description is kept on the process for thread spawns.
Scheduler: fsBase per thread, loaded into IA32_FS_BASE at every
dispatch site through a per-CPU cache - TLS-free processes cost one
MSR write per CPU ever, and userspace cannot desync the cache since
CR4.FSGSBASE stays off. SYS_THREAD_SPAWN gives each new thread its
own TLS block copied from the template (allocated from the process
heap; reclaimed at process teardown).
Ships tls-test.elf in the SDK (built by the devkit target): checks
.tdata values, .tbss zeroing, and the %fs:0 self-pointer, exiting
nonzero on failure. Boot-smoke verified; existing TLS-free programs
are unaffected.
Co-Authored-By: Claude Fable 5 <[email protected]>
Add build-montauk-toolchain.sh: builds an OS-aware cross GCC/binutils
(same versions and prefix as the bare-metal x86_64-elf toolchain) whose
x86_64-montauk target links static ET_EXEC binaries against the Montauk
libc sysroot with no special flags: 4 KiB max page size for the kernel
ELF loader, -mno-red-zone by default, crt1/crti/crtn + -lc from the
sysroot, __montauk__ defined. Target patches are checked into
toolchain/patches/, the GCC target header into toolchain/files/.
sys/types.h now includes <stdint.h> so hosted code (libgcov and
friends) sees intptr_t via the stdio include chain.
Co-Authored-By: Claude Fable 5 <[email protected]>
danielandClaude Fable 5