Stop SpringBoard while we are messing with lsd.

[uikittools.git] / iomfsetgamma.c

/* UIKit Tools - command-line utilities for UIKit
 * Copyright (C) 2008-2012  Jay Freeman (saurik)
*/

/* Modified BSD License {{{ */
/*
 *        Redistribution and use in source and binary
 * forms, with or without modification, are permitted
 * provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the
 *    above copyright notice, this list of conditions
 *    and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the
 *    above copyright notice, this list of conditions
 *    and the following disclaimer in the documentation
 *    and/or other materials provided with the
 *    distribution.
 * 3. The name of the author may not be used to endorse
 *    or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* }}} */

#include <mach/mach.h>

#include <stdio.h>
#include <stdlib.h>

#include <dlfcn.h>

#include <IOKit/IOKitLib.h>

#if 0
set -e

sdk=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk

/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/g++ \
    -Wall -fmessage-length=0 \
    -arch armv6 -miphoneos-version-min=2.0 \
    -isysroot "${sdk}" -I. -F"${sdk}"/System/Library/PrivateFrameworks \
    -framework IOKit -framework IOMobileFramebuffer \
    -o iomfsetgamma iomfsetgamma.c

ldid iomfsetgamma

exit 0
#endif

typedef void *IOMobileFramebufferRef;

kern_return_t IOMobileFramebufferOpen(io_service_t, mach_port_t, void *, IOMobileFramebufferRef *);
kern_return_t IOMobileFramebufferSetGammaTable(IOMobileFramebufferRef, void *);
kern_return_t (*$IOMobileFramebufferGetGammaTable)(IOMobileFramebufferRef, void *);

#define _assert(test) \
    if (!(test)) { \
        fprintf(stderr, "_assert(%s)\n", #test); \
        exit(-1); \
    }

int main(int argc, char *argv[]) {
    if (argc != 4) {
        fprintf(stderr, "usage: iomfsetgamma <red> <green> <blue>\n");
        fprintf(stderr, "  example: 1.00 0.78 0.64\n");
        return 1;
    }

    unsigned rs = strtod(argv[1], NULL) * 0x100;
    _assert(rs <= 0x100);

    unsigned gs = strtod(argv[2], NULL) * 0x100;
    _assert(gs <= 0x100);

    unsigned bs = strtod(argv[3], NULL) * 0x100;
    _assert(bs <= 0x100);

    kern_return_t error;
    mach_port_t self = mach_task_self();

    io_service_t service = 0;

    if (service == 0)
        service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleCLCD"));
    if (service == 0)
        service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleH1CLCD"));
    if (service == 0)
        service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleM2CLCD"));

    _assert(service != 0);

    IOMobileFramebufferRef fb;
    error = IOMobileFramebufferOpen(service, self, 0, &fb);
    _assert(error == 0);

    uint32_t data[0xc00 / sizeof(uint32_t)];
    memset(data, 0, sizeof(data));

    FILE *file = fopen("/tmp/.iomfgamma.dat", "rb");
    if (file == NULL) {
        $IOMobileFramebufferGetGammaTable = dlsym(RTLD_DEFAULT, "IOMobileFramebufferGetGammaTable");
        _assert($IOMobileFramebufferGetGammaTable != NULL);
        error = $IOMobileFramebufferGetGammaTable(fb, data);
        _assert(error == 0);

        file = fopen("/tmp/.iomfgamma.dat", "wb");
        _assert(file != NULL);

        fwrite(data, 1, sizeof(data), file);
        fclose(file);

        file = fopen("/tmp/.iomfgamma.dat", "rb");
        _assert(file != NULL);
    }

    fread(data, 1, sizeof(data), file);
    fclose(file);

    size_t i;
    for (i = 0; i != 256; ++i) {
        int j = 255 - i;

        int r = j * rs >> 8;
        int g = j * gs >> 8;
        int b = j * bs >> 8;

        data[j + 0x000] = data[r + 0x000];
        data[j + 0x100] = data[g + 0x100];
        data[j + 0x200] = data[b + 0x200];
    }

    error = IOMobileFramebufferSetGammaTable(fb, data);
    _assert(error == 0);

    return 0;
}