1 /* Copyright (c) 2014 The Chromium OS Authors. All rights reserved. 2 * Use of this source code is governed by a BSD-style license that can be 3 * found in the LICENSE file. 4 * 5 * Stub implementations of stream APIs. 6 */ 7 8 #include <stdint.h> 9 10 #define _STUB_IMPLEMENTATION_ 11 12 #include "vboot_api.h" 13 14 /* The stub implementation assumes 512-byte disk sectors */ 15 #define LBA_BYTES 512 16 17 /* Internal struct to simulate a stream for sector-based disks */ 18 struct disk_stream { 19 /* Disk handle */ 20 VbExDiskHandle_t handle; 21 22 /* Next sector to read */ 23 uint64_t sector; 24 25 /* Number of sectors left in partition */ 26 uint64_t sectors_left; 27 }; 28 29 VbError_t VbExStreamOpen(VbExDiskHandle_t handle, uint64_t lba_start, 30 uint64_t lba_count, VbExStream_t *stream) 31 { 32 struct disk_stream *s; 33 34 if (!handle) { 35 *stream = NULL; 36 return VBERROR_UNKNOWN; 37 } 38 39 s = VbExMalloc(sizeof(*s)); 40 s->handle = handle; 41 s->sector = lba_start; 42 s->sectors_left = lba_count; 43 44 *stream = (void *)s; 45 46 return VBERROR_SUCCESS; 47 } 48 49 VbError_t VbExStreamRead(VbExStream_t stream, uint32_t bytes, void *buffer) 50 { 51 struct disk_stream *s = (struct disk_stream *)stream; 52 uint64_t sectors; 53 VbError_t rv; 54 55 if (!s) 56 return VBERROR_UNKNOWN; 57 58 /* For now, require reads to be a multiple of the LBA size */ 59 if (bytes % LBA_BYTES) 60 return VBERROR_UNKNOWN; 61 62 /* Fail on overflow */ 63 sectors = bytes / LBA_BYTES; 64 if (sectors > s->sectors_left) 65 return VBERROR_UNKNOWN; 66 67 rv = VbExDiskRead(s->handle, s->sector, sectors, buffer); 68 if (rv != VBERROR_SUCCESS) 69 return rv; 70 71 s->sector += sectors; 72 s->sectors_left -= sectors; 73 74 return VBERROR_SUCCESS; 75 } 76 77 void VbExStreamClose(VbExStream_t stream) 78 { 79 struct disk_stream *s = (struct disk_stream *)stream; 80 81 /* Allow freeing a null pointer */ 82 if (!s) 83 return; 84 85 VbExFree(s); 86 return; 87 } 88
