SchOS/include/fcntl.h
Nexoniarz e04ca28812 Rename Schunix to SchOS; the kernel becomes SchIFT
Removes the "-unix" element and with it any trademark exposure to The
Open Group.

The split follows the ecosystem layout: SchOS is the system, and the
kernel has its own name. Kernel-identity strings are the only places
that take SchIFT -- uname(2) sysname, /proc/version, and the two licence
sentences that say "kernel" outright. That is what every Unix does here:
`uname -s` on Linux reports the kernel, not the distribution. Everything
a user reads as the product -- panic screen, boot menu, error prefixes,
docs, LICENSE, NOTICE -- is SchOS.

schunix.img is schos.img, the logo assets and the musl TLS patch are
renamed, and __SCHUNIX__ is __SCHOS__ (the define and the patch that
consumes it moved together).

Two things the rename broke, both found by the bootcheck suite:

  - shmtest wrote "SCHUNIX-MMAP-OK" with a hardcoded length of 15 and
    compared it back by hand-counted offsets (m[3]=='U', m[14]=='K').
    The shorter marker left the write running two bytes past the literal
    and the compare reading past the data, failing a file-backed mmap
    that was working correctly. Now written and compared through one
    constant with sizeof.
  - bootcheck asserted a 31-byte file after appending to
    "hello-from-schunix"; the shorter string makes it 29.

Both are the same mistake: a string literal whose length is written out
somewhere else. Full suite green -- base, Tty, Ps, Sock, Fb, Usb, Evdev.
2026-08-09 14:09:59 +02:00

43 lines
1.9 KiB
C

#pragma once
// open(2) flags.
//
// These are the *Linux x86-64* values, and they have to be: every program in
// the userland is built against a libc that sends Linux flag values, and the
// kernel reads them with these constants. They disagreed for a long time, with
// results that looked like filesystem corruption rather than like a mistake --
// Linux O_APPEND (0x400) landed on SchOS's O_TRUNC, so `cmd >> file`
// truncated the file it was meant to extend, and Linux O_TRUNC (0x200) landed
// on O_CREATE, so `cmd > file` left whatever was past the new end in place.
// Neither failure pointed anywhere near a header.
//
// Do not tidy these into a neat sequence. They are an external interface.
#define O_RDONLY 0x000000
#define O_WRONLY 0x000001
#define O_RDWR 0x000002
#define O_ACCMODE 0x000003
#define O_CREATE 0x000040 /* Linux O_CREAT (0100) */
#define O_CREAT O_CREATE /* the spelling every program uses */
#define O_EXCL 0x000080 /* Linux O_EXCL (0200) */
#define O_NOCTTY 0x000100 /* Linux O_NOCTTY (0400) */
#define O_TRUNC 0x000200 /* Linux O_TRUNC (01000) */
#define O_APPEND 0x000400 /* Linux O_APPEND (02000) */
#define O_NONBLOCK 0x000800 /* Linux O_NONBLOCK (04000); no-op here */
#define O_DIRECTORY 0x010000 /* Linux O_DIRECTORY (0200000) */
#define O_NOFOLLOW 0x020000 /* Linux O_NOFOLLOW (0400000) */
#define O_CLOEXEC 0x080000 /* Linux O_CLOEXEC (02000000) */
// SchOS-only, placed above every flag Linux defines so it can never be
// mistaken for one. 0x40000 was used before and collides with Linux O_NOATIME.
#define O_EXTENT 0x8000000 /* sparse-extent hint */
#define F_DUPFD 0
#define F_GETFD 1
#define F_SETFD 2
#define F_GETFL 3
#define F_SETFL 4
#define F_DUPFD_CLOEXEC 1030 // Linux value
#define FD_CLOEXEC 1