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Subject:
question about customized frame buffer driver
From: "Allen Yang" ####@####.#### Date: 10 Sep 2007 22:55:31 +0100 Message-Id: <33B07717EB1E594F934D63BE3BDA5A3FA206D9@itexch01.nucomm.local> Hi, Unlike other LCD controllers, which use a part of "system memory" as its "Display memory", my system is interfaced with a LCD panel (which has LCD controller, LCD and Display memory). It's only connected to CPU by Data Bus, NO address bus. The LCD panel's Display memory is accessible only through "data register" of LCD controller. I have to write the "address" of Display RAM first to the "data register" and then the "data" to the "data register". In this case, the normal *mmap* done by fbmem.c would not work here. I am currently writing the frame buffer for the above LCD in uClinux 2.6.17. Basically I got some display on the LCD. However, I still have some questions: (1) When I kill the nano-X process, I got the following message, and system dies. # ****************munmap of non-mmaped memory by process 146 (nano-X): 40cc0000 What's the meaning of this message? In the above, process 146 is the Nano-X process. 0x40cc0000 is starting address of my frame buffer. (2) I implemented a special command "FBIO_UPDATE_SCREEN" in function lcdfb_ioctl(). In this command, I just send all the data in my frame buffer to the LCD RAM. In my Nano-X application, first I call Nano-X APIs (GrText()...) to prepare the LCD display, then I call "GrFlush()". Then I call my own lcdfb_ioctl() with command "FBIO_UPDATE_SCREEN". I thought the LCD should display what I just prepared. For example, I want to display the following screens: SCREEN 1 -> SCREEN 2 -> SCREEN 3 -> SCREEN 4 -> SCREEN 5... LCD always displays the previous SCREEN instead of the current SCREEN. How could this happen? Does "GrFlush()" send Nano-X buffered message into my LCD frame buffer? Any suggestions will be highly appreciated! Regards, Allen The information contained in this email and attachments to this email are the proprietary and confidential property of Nucomm, Inc. The information is provided in strict confidence and shall not be reproduced, copied, or used (partially or wholly) in any manner without prior, express written authorization of Nucomm, Inc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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