Document directory
Step 1 Add the sd_card folder to the APP project path
Step 2 write code
Step 3 call the SD card driver Function
In the previous section, we completed the configuration of the niosii SBTE. The following describes how to compile an SD card Driver Base
. getexternalstoragestate (). Equals (environment. media_mounted )){// Obtain the storage directory corresponding to the SD cardFile sdcarddir = environment. getexternalstoragedirectory ();// Obtain the input stream corresponding to the specified fileFileinputstream FCM = new fileinputstream (sdcarddir. GetCanonicalPath () + file_name );// Package the specified input stream into bufferedreaderBufferedreader BR = new bufferedreader (New inputstreamread
before the related SD initialization work can be performed, he can still initialize it.
for(i=0;i
However, it may be better to perform initialization more successfully. Therefore, we have to give it 74 clocks. It doesn't matter!
2. The protocol says that when we reset or power on, the SD control register of the SD
that the difference is that the size of the boot partition we set up is 100M, and the type of partition that created boot is also Linux.
Then format the boot partition:sudo mkfs.vfat -F 32 -n "boot" /dev/sde1
To format the ROOTFS partition:sudo mkfs.ext4 -L "rootfs" /dev/sde2Here we have completed the SD card production.
5 Burn write SD boot
1. As shown in the figure below, we use our fingers to gently fasten the top slot with our finger, and remove the back cover to be fine and don't spoil it.
2 Then we push the SD card into the slot until it is stuck.
Note: Please make sure the golden touch of the SD ca
Causes of SD card data loss
Why are SD card files lost? Is the opening method incorrect? Or cannot the SD card be read by the computer? In fact, there are various factors that may cause SD
TF card, is not supported by all handsets, but sometimes some of the exotic needs are first stored in the TF card, which calls for a developer to check if the card exists and is available. And because this is a mobile phone manufacturer can expand, customizable part, all the mobile phones produced by different manufacturers, and the same manufacturer of differen
computer. Question: Why not use the DF command here?The reason is that if your TF/SD card has only one partition but the partition is corrupted, or there are multiple partitions but there is no identifiable partition, then the DF command is unable to see the TF/SD card, so it is the ultimate solution to list the devic
SD Card write protection How to remove the solution:
Step 1, about the SD card write protection How to remove the problem, you can use the disk repair program to repair the SD card. Open My Computer, locate the
As Android learns, when we open the input and output streams of files through openfileinput or openfileoutput of context, all files in the data folder of the application are opened by the program lock, the size of the files stored in this way may be limited-after all, the built-in storage space of the mobile phone is limited.
In order to better access the application's big file data, the application needs to read and write files on the SD
In the mobile phone use of the process began to often have friends with the mobile phone SD card can not be formatted to read the problem, for the SD card can not be formatted to produce a lot of reasons, but many cases are some small problems, the following teach you how to solve the
the SD card virus detection, did not find, eliminate virus damage. Then on the computer test, found that the SD card letter appears, double-click the letter, and the "whether to format" prompts to view the attributes, card capacity increased to 544GB, and the actual capacit
First, the SD card burning writing system basic idea:(1) Write uboot.bin to sd card(2) Copy image entire folder to SD card(3) The Development Board starts from the
shortcut on the desktop! After the simulator is started, we will find out how the connected SD card has changed.
Hey, don't worry! Because we still need to complete this last 20% step to truly "Insert" the SD card to the android SDK 1.5 simulator!
Method 1,
Right-click the simulator shortcut that was origi
card), but the system cannot ensure that the application will certainly be installed to extended storage. If the extended storage has no space or is unavailable, the system will still install the application in Ram.
Auto -- it means that this application may be installed to the extended storage, but there is no special preference for the installation location, there will be systems based on their ownAlgorithmTo determine where to install the applic
Tags: I/O use data on as ACM C ash cannot For sd I/O cards, the card recognition process is as follows:1. The bus is activated.2. The sdio host sends the io_send_op_cond (limit 5) command.3. The response is the contents of the card's operation condition register;-If there is a response and the MP bit in the response is 0, it indicates that the
:# make Arch=arm Cross_compile=arm-linux-gnueabi HF -Uimage here to note is that the marked place cannot be less than the compilation error When this is finish ' s you'll have uimage ready and you can build the kernel modules:# Make Arch=arm cross_compile=arm-linux-gnueabi-install_mod_path=out modules# Make Arch=arm cross_compile=arm-linux-gnueabi-install_mod_path=out Modules_installFormat and setup the Sd-card
, otherwise in the upper application software will appear to find the SD card,
2 in the Android kernel configuration (Linux kernel configuration) , note: The general Setup-> enable deprecated Sysfs features to support old Userspac E tools can be canceled, otherwise it may affect the Vold detection SD
/sdcard/
L be case sensitive!Fat: utf8 is not a recommended Io charset for fat filesystems, filesystem will BE case sensitive!Mount: invalid argument
If you mount mmcblk0, this error message is displayed, and mmcblk0p1 is successfully mounted. Of course, you should not manually mount it under Android. Otherwise, the SD card cannot be found in the upper-layer application software,
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