84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
/*
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* Copyright (c) 2009 Travis Geiselbrecht
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*
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* Use of this source code is governed by a MIT-style
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* license that can be found in the LICENSE file or at
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* https://opensource.org/licenses/MIT
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*/
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#include <lk/debug.h>
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#include <lk/trace.h>
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#include <string.h>
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#include <stdlib.h>
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#include <lib/bio.h>
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#define LOCAL_TRACE 0
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#define BLOCKSIZE 512
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typedef struct mem_bdev {
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bdev_t dev; // base device
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void *ptr;
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} mem_bdev_t;
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static ssize_t mem_bdev_read(bdev_t *bdev, void *buf, off_t offset, size_t len) {
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mem_bdev_t *mem = (mem_bdev_t *)bdev;
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LTRACEF("bdev %s, buf %p, offset %lld, len %zu\n", bdev->name, buf, offset, len);
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memcpy(buf, (uint8_t *)mem->ptr + offset, len);
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return len;
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}
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static ssize_t mem_bdev_read_block(struct bdev *bdev, void *buf, bnum_t block, uint count) {
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mem_bdev_t *mem = (mem_bdev_t *)bdev;
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LTRACEF("bdev %s, buf %p, block %u, count %u\n", bdev->name, buf, block, count);
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memcpy(buf, (uint8_t *)mem->ptr + block * BLOCKSIZE, count * BLOCKSIZE);
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return count * BLOCKSIZE;
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}
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static ssize_t mem_bdev_write(bdev_t *bdev, const void *buf, off_t offset, size_t len) {
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mem_bdev_t *mem = (mem_bdev_t *)bdev;
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LTRACEF("bdev %s, buf %p, offset %lld, len %zu\n", bdev->name, buf, offset, len);
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memcpy((uint8_t *)mem->ptr + offset, buf, len);
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return len;
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}
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static ssize_t mem_bdev_write_block(struct bdev *bdev, const void *buf, bnum_t block, uint count) {
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mem_bdev_t *mem = (mem_bdev_t *)bdev;
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LTRACEF("bdev %s, buf %p, block %u, count %u\n", bdev->name, buf, block, count);
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memcpy((uint8_t *)mem->ptr + block * BLOCKSIZE, buf, count * BLOCKSIZE);
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return count * BLOCKSIZE;
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}
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int create_membdev(const char *name, void *ptr, size_t len) {
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mem_bdev_t *mem = malloc(sizeof(mem_bdev_t));
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/* set up the base device */
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bio_initialize_bdev(&mem->dev, name, BLOCKSIZE, len / BLOCKSIZE, 0, NULL,
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BIO_FLAGS_NONE);
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/* our bits */
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mem->ptr = ptr;
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mem->dev.read = mem_bdev_read;
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mem->dev.read_block = mem_bdev_read_block;
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mem->dev.write = mem_bdev_write;
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mem->dev.write_block = mem_bdev_write_block;
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/* register it */
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bio_register_device(&mem->dev);
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return 0;
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}
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