Texas Instruments TI89 Developer Guide - Page 78
Signature, Layout in Memory - factorial
UPC - 033317198566
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36 Chapter 7: Flash Application Layout 7.1.7. 7.2. Signature The signature protects everything from the beginning of the certificate header to the end of the application from changes. Layout in Memory The OS creates an Application Control Block (ACB) for each app in the calculator whether it is one of the built-in apps that come preinstalled from the factory or installed later as a Flash app. Routine EV_getAppID returns the ID of an app given its internal name. By design, the app ID is also the handle to the app's ACB. Dereference the handle to get a pointer to the app's ACB. ACB * pacb = (ACB *)HeapDeref(EV_getAppID(name)); ACBs form a linked list in memory. Global OS variable OO_firstACB contains a handle to the first ACB. Routines OO_NextACB and OO_PrevACB are used to traverse the list of ACBs. The Application Control Block contains information about the current state of the app. Here is a description of the ACB structure. USHORT flags - Application control flags: 0x0001 - ACB_BUILTIN, the app is a built-in application. 0x0002 - ACB_INSTALLED, the OS sets this flag when app installation is complete. 0x0004 - ACB_LOCALIZER, the app is a language localizer, i. e. its name appears in the MODE screen as a language choice. 0x0008 - ACB_LOCK, reserved. 0x0010 - ACB_JT_VERSION, jump table version mismatch, do not show on the APPS pop-up menu. 0x0020 - ACB_SELECTED, app is selected in the VAR-LINK screen. 0x0800 - ACB_COLLAPSE, collapse view of TI_BASIC extension functions and commands in the VAR_LINK screen. TI-89 / TI-92 Plus Developer Guide Not for Distribution Beta Version January 26, 2001