danielandClaude Fable 5
778f897f1a
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]>
2.6 KiB
MontaukOS Toolchains
Two cross toolchains live here, both installed to toolchain/local/:
| Script | Triple | Purpose |
|---|---|---|
build-toolchain.sh |
x86_64-elf |
Bare-metal compiler for the kernel |
build-montauk-toolchain.sh |
x86_64-montauk |
OS-aware compiler for userspace programs |
Both use Binutils 2.43.1 + GCC 14.2.0 and share the source trees in
src/. The Montauk target is added by the patches in patches/ plus
the target header files/montauk.h (installed as
gcc/config/montauk.h in the GCC tree).
The x86_64-montauk target
x86_64-montauk-gcc knows the Montauk userspace ABI, so a hosted
program builds with no special flags:
toolchain/local/bin/x86_64-montauk-gcc hello.c -o hello.elf
What the target does by default:
- Links static, non-PIE
ET_EXECbinaries (what the kernel ELF loader inkernel/src/Sched/ElfLoader.cppaccepts), text at 0x400000. -z max-page-size=0x1000— the loader maps 4 KiB pages; the x86-64 default of 2 MiB segment alignment would bloat every binary.- Startup/link line:
crt1.o crti.o crtbegin.o ... -lc crtend.o crtn.otaken from the sysroot (toolchain/sysroot/usr/lib), which is assembled fromprograms/lib/libcby the build script. - Headers resolve against the sysroot (
toolchain/sysroot/usr/include), assembled fromprograms/include/libcplus themontauk/SDK headers.#include <stdio.h>just works; no-nostdincneeded. -mno-red-zone(the project-wide userspace convention). Standard hard-float SysV ABI otherwise; pass-mno-sseetc. per program if wanted.- Defines
__montauk__/__MONTAUK__.
C++ works with -fno-exceptions -fno-rtti (the project convention).
There is no libstdc++ yet — only libgcc is built. A hosted libstdc++
needs a more complete libc and is the next step toward self-hosting.
Refreshing the sysroot
The sysroot is rebuilt every time build-montauk-toolchain.sh runs
(the compiler build steps are skipped once installed). After changing
libc headers or the libc itself, re-run the script to refresh it.
Layout
toolchain/
build-toolchain.sh # bare-metal x86_64-elf (kernel)
build-montauk-toolchain.sh # x86_64-montauk (userspace)
patches/ # Montauk target patches (checked in)
files/montauk.h # GCC target header (checked in)
src/ # downloaded + patched sources (ignored)
build/ # build trees (ignored)
local/ # install prefix (ignored)
sysroot/ # generated target sysroot (ignored)