Difference between revisions of "GSCapability"

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This shared memory is constructed by the [[SBPlatformController]] class in {{applink|SpringBoard}}.
  
 
== Default capabilities of various devices ==
 
== Default capabilities of various devices ==

Revision as of 19:38, 18 April 2010


GSCapability is a group of C functions that checks the capability of the device. A capability can be a simple boolean value, e.g. whether the device can take pictures, to a complex structure e.g. the screen dimensions.

Example code

if (GSSystemHasCapability(kGSMagnetometerCapability)) {
  direction = get_direction();
} else {
  printf("This device has no compass\n");
}

Extracting the capability dictionary

The capabilities are stored as a plist in a shared memory region named "GSCapabilities". You can use this code to extract it:

#include <sys/mman.h>
#include <sys/stat.h>
#include <CoreFoundation/CoreFoundation.h>
static CFDictionaryRef GSCopyCapababilities(void) {
	int shm = shm_open("GSCapabilities", 0);
	assert(shm != -1);
	
	struct stat shm_stat;
	int fstat_ret = fstat(shm, &shm_stat);
	assert(fstat_ret == 0);
	
	void* map = mmap(NULL, shm_stat.st_size, 1, 1, shm, 0);
	assert(map >= 0);
	
	CFIndex len = *(CFIndex*)map;
	CFDataRef data = CFDataCreateWithBytesNoCopy(NULL, (const UInt8*)map + sizeof(len), len, kCFAllocatorNull);
	assert(data != NULL);
	
	CFPropertyListRef propList = CFPropertyListCreateFromXMLData(NULL, data, kCFPropertyListImmutable, NULL);
	CFRelease(data);
	
	munmap(map, len);
	close(shm);
	
	return propList;
}

This shared memory is constructed by the SBPlatformController class in SpringBoard.

Default capabilities of various devices

Capabilities N45AP
(iPod Touch 1G)
M68AP
(iPhone 2G)
kGSTelephonyCapability
"telephony"
No Yes
kGSCellularDataCapability
"cellular-data"
No Unknown
kGSSMSCapability
"sms"
No Yes
kGSCameraCapability
"still-camera"
No Yes
kGSVideoCameraCapability
"video-camera"
No No
kGSAutoFocusCameraCapability
"auto-focus-camera"
No No
kGSH264EncoderCapability
"h264-encoder"
No No
kGSWiFiCapability
"wifi"
Yes Yes
kGSAccelerometerCapability
"accelerometer"
Yes Yes
kGSMagnetometerCapability
"magnetometer"
No No
kGSGPSCapability
"gps"
No Yes
kGSLocationServicesCapability
"location-services"
Yes Yes
kGSMicrophoneCapability
"microphone"
No Yes
kGSPeer2PeerCapability
"peer-peer"
No Unknown
kGSOpenGLES1Capability
"opengles-1"
Yes Yes
kGSOpenGLES2Capability
"opengles-2"
No No
kGSARMV6ExecutionCapability
"armv6"
Yes Yes
kGSARMV7ExecutionCapability
"armv7"
No No
kGSDisplayPortCapability
"display-port"
No Unknown
kGSContainsCellularRadioCapability
"contains-cellular-radio"
No Unknown
kGSVolumeButtonCapability
"volume-buttons"
No Yes
kGSRingerSwitchCapability
"ringer-switch"
No Yes
kGSPiezoClickerCapability
"piezo-clicker"
Yes No
kGSBluetoothCapability
"bluetooth"
No Yes
kGSUnifiedIPodCapability
"unified-ipod"
No Yes
kGSYouTubeCapability
"youtube"
Yes Yes
kGSYouTubePluginCapability
"youtubePlugin"
Yes Yes
kGSGreenTeaDeviceCapability[1]
"green-tea"
No No
kGSNotGreenTeaDeviceCapability[1]
"not-green-tea"
Yes Yes
kGSInternationalSettingsCapability
"international-settings"
Yes Yes
kGSPlatformStandAloneContactsCapability
"stand-alone-contacts"
Yes Yes
kGSDelaySleepForHeadsetClickCapability
"delay-sleep-for-headset-click"
No Unknown
kGSLaunchApplicationsWhileAnimatingCapability
"launch-applications-while-animating"
No Unknown
kGSLoadThumbnailsWhileScrollingCapability
"load-thumbnails-while-scrolling"
No Unknown
kGSSensitiveUICapability
"sensitive-ui"
No Unknown
kGSAppleInternalInstallCapability
"apple-internal-install"
No No
kGSHasAllFeaturesCapability
"all-features"
Yes Yes
kGSNikeIpodCapability
"nike-ipod"
No No
kGSApplicationInstallationCapability
"applicationInstallation"
Yes Yes
kGSVoiceControlCapability
"voice-control"
No No
kGSProximitySensorCapability
"proximity-sensor"
No Yes
kGSGasGaugeBatteryCapability[2]
"gas-gauge-battery"
No Unknown
kGSAccessibilityCapability
"accessibility"
No No
kGSMMSCapability
"mms"
No No
kGSEncryptedDataPartitionCapability
"encrypted-data-partition"
No Unknown
kGSEncodeAACCapability
"encode-aac"
No Unknown
kGS720pPlaybackCapability
"720p"
No No
kGSDisplayFCCLogosViaSoftwareCapability
"fcc-logos-via-software"
No Unknown
kGSHideNonDefaultApplicationsCapability
"hide-non-default-apps"
No Unknown
kGSWildcatCapability[3]
"wildcat"
No No
kGSDataPlanCapability
"data-plan"
No Unknown
kGSCameraFlashCapability
"camera-flash"
No Unknown
kGSCanRasterizeEfficientlyCapability
"can-rasterize-efficiently"
Unknown Unknown
kGSFrontFacingCameraCapability
"front-facing-camera"
No No
kGSHiDPICapability
"horiz"
Unknown Unknown
kGSIOSurfaceBackedImagesCapability
"io-surface-backed-images"
Unknown Unknown
kGSMultitaskingCapability
"multitasking"
No No
kGSVeniceCapability
"venice"
Unknown Unknown
kGSTelephonyMaximumGeneration
"telephony-maximum-generation"
0 2.5
kGSDeviceNameString
"device-name"
iPod iPhone
kGSMarketingNameString
"marketing-name"
iPod Touch iPhone
kGSScreenDimensionsCapability[4]
"screen-dimensions"
320 × 480 320 × 480

References

  1. 1.0 1.1 "Green-Tea" is a code name for devices sold in China. Green-Tea devices have restricted access to various applications e.g. Maps.
  2. Gas-gauge capability allows accurate monitoring of the battery level
  3. "Wildcat" is the codename of iPad.
  4. This capability is a dictionary with 4 members. Only width and height are shown here.