vasilito
068a1ca63e
Bootloader fork rebase:
- Base changed from 0.1.0 pre-patched archive to upstream 1.0.0 tag (c7eeb9f)
- Applied 0001-redbear-local-forks.patch (Cargo.toml crate path redirects)
- Applied fix-uefi-alloc-panic.patch equivalents (4 panic!() -> graceful
error handling in src/main.rs)
- Applied P5-live-preload-cap-1gib.patch (1 GiB cap on live image preload)
- Skipped: P0 GPT partition scan (requires new module + integration),
P1 timeout/default-resolution, P2 live preload guard (subsumed by
panic fixes + cap), P3 live image safe read, P4 large ISO boot,
redox.patch — to be applied in dedicated rebase session.
firmware-loader/Cargo.toml: version 0.1.0 -> 0.3.0 (sync with other
Red Bear custom crates which are at 0.3.0).
fork-upstream-map.toml: bootloader back from PENDING_REBASE to 1.0.0
since the partial rebase matches upstream 1.0.0 content.
fork-upstream-map.toml: base restored to 'main' tracked (was correctly
tracked by build-redbear.sh).
83 lines
3.1 KiB
C
83 lines
3.1 KiB
C
/* Return a pointer to a zero-size object in memory.
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Copyright (C) 2009-2025 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* ISO C 99 does not allow memcmp(), memchr() etc. to be invoked with a NULL
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argument. Therefore this file produces a non-NULL pointer which cannot
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be dereferenced, if possible. */
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/* On Android, when targeting Android 4.4 or older with a GCC toolchain,
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prevent a compilation error
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"error: call to 'mmap' declared with attribute error: mmap is not
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available with _FILE_OFFSET_BITS=64 when using GCC until android-21.
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Either raise your minSdkVersion, disable _FILE_OFFSET_BITS=64, or
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switch to Clang."
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The files that we access in this compilation unit are less than 2 GB
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large. */
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#if defined __ANDROID__
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# undef _FILE_OFFSET_BITS
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# undef __USE_FILE_OFFSET64
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#endif
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#include <stdlib.h>
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/* Test whether mmap() and mprotect() are available.
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We don't use HAVE_MMAP, because AC_FUNC_MMAP would not define it on HP-UX.
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HAVE_MPROTECT is not enough, because mingw does not have mmap() but has an
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mprotect() function in libgcc.a.
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And OS/2 kLIBC has <sys/mman.h> and mprotect(), but not mmap(). */
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#if HAVE_SYS_MMAN_H && HAVE_MPROTECT && !defined __KLIBC__
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# include <fcntl.h>
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# include <unistd.h>
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# include <sys/types.h>
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# include <sys/mman.h>
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/* Define MAP_FILE when it isn't otherwise. */
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# ifndef MAP_FILE
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# define MAP_FILE 0
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# endif
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#endif
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/* Return a pointer to a zero-size object in memory (that is, actually, a
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pointer to a page boundary where the previous page is readable and writable
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and the next page is neither readable not writable), if possible.
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Return NULL otherwise. */
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static void *
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zerosize_ptr (void)
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{
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/* Use mmap and mprotect when they exist. Don't test HAVE_MMAP, because it is
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not defined on HP-UX 11 (since it does not support MAP_FIXED). */
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#if HAVE_SYS_MMAN_H && HAVE_MPROTECT && !defined __KLIBC__
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# if HAVE_MAP_ANONYMOUS
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const int flags = MAP_ANONYMOUS | MAP_PRIVATE;
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const int fd = -1;
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# else /* !HAVE_MAP_ANONYMOUS */
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const int flags = MAP_FILE | MAP_PRIVATE;
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int fd = open ("/dev/zero", O_RDONLY, 0666);
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if (fd >= 0)
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# endif
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{
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size_t pagesize = sysconf (_SC_PAGESIZE);
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char *two_pages =
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(char *) mmap (NULL, 2 * pagesize, PROT_READ | PROT_WRITE,
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flags, fd, 0);
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if (two_pages != (char *)(-1)
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&& mprotect (two_pages + pagesize, pagesize, PROT_NONE) == 0)
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return two_pages + pagesize;
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}
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#endif
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return NULL;
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}
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