101 lines
2.1 KiB
C
101 lines
2.1 KiB
C
// ramdisk.c
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// Author: Josh Holtrop
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// Date: 08/20/04
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// Modified: 08/22/04
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#include "block/ramdisk.h"
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#include "fs/devices.h"
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#include "functions.h"
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#include "mm/vmm.h"
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#include "lang/asmfuncs.h"
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ramdisk_t *ramdisks[256];
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int ramdisk_init(major_t major)
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{
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dev_driver_t *ramdisk_driver;
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if (( ramdisk_driver = New(dev_driver_t) ))
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{
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ramdisk_driver->block_read = ramdisk_block_read;
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ramdisk_driver->block_write = ramdisk_block_write;
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devices_register_major('b', major, ramdisk_driver);
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return 0;
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}
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return -1;
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}
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minor_t ramdisk_new(u32_t size)
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{
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int i;
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for (i = 0; i < 256; i++)
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{
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if (!ramdisks[i])
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{
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void *start;
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if (( start = kmalloc(size) ))
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{
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ramdisks[i] = New(ramdisk_t);
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ramdisks[i]->start = start;
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ramdisks[i]->size = size;
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return i;
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}
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return -2;
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}
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}
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return -1;
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}
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minor_t ramdisk_register(void *ramdisk, u32_t size)
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{
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int i;
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for (i = 0; i < 256; i++)
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{
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if (!ramdisks[i])
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{
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ramdisks[i] = New(ramdisk_t);
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ramdisks[i]->start = ramdisk;
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ramdisks[i]->size = size;
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return i;
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}
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}
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return -1;
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}
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int ramdisk_remove(minor_t minor)
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{
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if (ramdisks[minor])
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{
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kfree(ramdisks[minor]->start);
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kfree(ramdisks[minor]);
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ramdisks[minor] = NULL;
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return 0;
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}
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return -1;
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}
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int ramdisk_block_read(minor_t minor, u32_t blockNum, u32_t count, void *buffer)
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{
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if (!ramdisks[minor])
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return -1;
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if ((blockNum << BLOCK_SIZE_LOG) >= ramdisks[minor]->size)
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return -2;
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void *rdAddr = ramdisks[minor]->start + (blockNum << BLOCK_SIZE_LOG);
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u32_t copyLen = min(count << BLOCK_SIZE_LOG, ramdisks[minor]->size - (u32_t)rdAddr);
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memcpyd(buffer, rdAddr, copyLen >> 2);
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return copyLen;
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}
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int ramdisk_block_write(minor_t minor, u32_t blockNum, u32_t count, void *buffer)
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{
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if (!ramdisks[minor])
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return -1;
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if ((blockNum << BLOCK_SIZE_LOG) >= ramdisks[minor]->size)
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return -2;
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void *rdAddr = ramdisks[minor]->start + (blockNum << BLOCK_SIZE_LOG);
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u32_t copyLen = min(count << BLOCK_SIZE_LOG, ramdisks[minor]->size - (u32_t)rdAddr);
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memcpyd(rdAddr, buffer, copyLen >> 2);
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return copyLen;
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}
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