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73 lines
1.8 KiB
Markdown
73 lines
1.8 KiB
Markdown
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# ramdisk
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A ramdisk block device based on RT-Thread device driver framework.
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It works as a block device which allows to be format to most of the filesystems supported by RT-Thread.
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这是一个基于 RTT block device 的 ramdisk 块设备。除了能被文件系统格式化，还能当一般的块设备来存储数据。
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## Usage
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Call to create a ramdisk block device.
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调用以下接口即可新建一个 ramdisk 设备，并注册到 RTT 的块设备链表。
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`ramdisk_init(char *name, rt_uint8_t* addr, rt_size_t block_size, rt_size_t num_block);`
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name: device name.
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addr: the start address of the memory block. Can pass NULL to use stack memory.
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block_size: block size in byte.
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num_block: the number of blocks.
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## Examples
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This example does:
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- Initialise a ramdisk with size of 2MB, block size of 512.
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- Format it using elmFAT and mount it on root directory.
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- Then, create a few folders as mounting point for SD card or storage temporary caching files.
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```C
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/* Initialize the filesystem */
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int filesystem_init(void)
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{
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// ramdisk as root
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if(rt_device_find("ramdisk0"))
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{
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// format the ramdisk
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mkfs("elm", "ramdisk0");
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/* mount ramdisk0 as root directory */
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if (dfs_mount("ramdisk0", "/", "elm", 0, RT_NULL) == 0)
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{
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LOG_I("ramdisk mounted on \"/\".");
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/* now you can create dir dynamically. */
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mkdir("/sd", 0x777);
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mkdir("/cache", 0x777);
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mkdir("/download", 0x777);
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}
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else
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{
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LOG_E("root folder creation failed!\n");
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}
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return RT_EOK;
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}
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LOG_E("cannot find ramdisk device");
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return RT_ERROR;
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}
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INIT_ENV_EXPORT(filesystem_init);
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int ramdisk_device_init(void)
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{
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ramdisk_init("ramdisk0", NULL, 512, 4096);
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return RT_EOK;
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}
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INIT_DEVICE_EXPORT(ramdisk_device_init);
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```
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