Lazily allocated heap-backed block device. When writing data of ROM address, heap memory is not used.

Dependents:   GR-PEACH-webcam GR-PEACH_DR_STRANGE_VR_GAME GR-Boards_WebCamera

Revision:
0:3e16bac28356
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RomRamBlockDevice.cpp	Tue May 16 04:24:46 2017 +0000
@@ -0,0 +1,160 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "RomRamBlockDevice.h"
+
+
+RomRamBlockDevice::RomRamBlockDevice(bd_size_t size, bd_size_t block)
+    : _read_size(block), _program_size(block), _erase_size(block)
+    , _count(size / block), _blocks(0), _rom_start(0xFFFFFFFF), _rom_end(0xFFFFFFFF)
+{
+    MBED_ASSERT(_count * _erase_size == size);
+}
+
+RomRamBlockDevice::RomRamBlockDevice(bd_size_t size, bd_size_t read, bd_size_t program, bd_size_t erase)
+    : _read_size(read), _program_size(program), _erase_size(erase)
+    , _count(size / erase), _blocks(0), _rom_start(0xFFFFFFFF), _rom_end(0xFFFFFFFF)
+{
+    MBED_ASSERT(_count * _erase_size == size);
+}
+
+RomRamBlockDevice::~RomRamBlockDevice()
+{
+    if (_blocks) {
+        for (size_t i = 0; i < _count; i++) {
+            free(_blocks[i]);
+        }
+
+        delete[] _blocks;
+        _blocks = 0;
+    }
+}
+
+void RomRamBlockDevice::SetRomAddr(uint32_t rom_start_addr, uint32_t rom_end_addr) {
+    _rom_start = rom_start_addr;
+    _rom_end = rom_end_addr;
+}
+
+int RomRamBlockDevice::init()
+{
+    if (!_blocks) {
+        _blocks = new uint8_t*[_count];
+        for (size_t i = 0; i < _count; i++) {
+            _blocks[i] = 0;
+        }
+    }
+
+    return BD_ERROR_OK;
+}
+
+int RomRamBlockDevice::deinit()
+{
+    // Heapory is lazily cleaned up in destructor to allow
+    // data to live across de/reinitialization
+    return BD_ERROR_OK;
+}
+
+bd_size_t RomRamBlockDevice::get_read_size() const
+{
+    return _read_size;
+}
+
+bd_size_t RomRamBlockDevice::get_program_size() const
+{
+    return _program_size;
+}
+
+bd_size_t RomRamBlockDevice::get_erase_size() const
+{
+    return _erase_size;
+}
+
+bd_size_t RomRamBlockDevice::size() const
+{
+    return _count * _erase_size;
+}
+
+int RomRamBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
+{
+    MBED_ASSERT(is_valid_read(addr, size));
+    uint8_t *buffer = static_cast<uint8_t*>(b);
+
+    while (size > 0) {
+        bd_addr_t hi = addr / _erase_size;
+        bd_addr_t lo = addr % _erase_size;
+
+        if (_blocks[hi]) {
+            memcpy(buffer, &_blocks[hi][lo], _read_size);
+        } else {
+            memset(buffer, 0, _read_size);
+        }
+
+        buffer += _read_size;
+        addr += _read_size;
+        size -= _read_size;
+    }
+
+    return 0;
+}
+
+int RomRamBlockDevice::program(const void *b, bd_addr_t addr, bd_size_t size)
+{
+    MBED_ASSERT(is_valid_program(addr, size));
+    const uint8_t *buffer = static_cast<const uint8_t*>(b);
+
+    while (size > 0) {
+        bd_addr_t hi = addr / _erase_size;
+        bd_addr_t lo = addr % _erase_size;
+
+        if (isRomAddress(buffer)) {
+            if (!isRomAddress(_blocks[hi])) {
+                free(_blocks[hi]);
+            }
+            _blocks[hi] = (uint8_t*)buffer;
+        } else {
+            if (!_blocks[hi]) {
+                _blocks[hi] = (uint8_t*)malloc(_erase_size);
+                if (!_blocks[hi]) {
+                    return BD_ERROR_DEVICE_ERROR;
+                }
+            }
+            memcpy(&_blocks[hi][lo], buffer, _program_size);
+        }
+
+        buffer += _program_size;
+        addr += _program_size;
+        size -= _program_size;
+    }
+
+    return 0;
+}
+
+int RomRamBlockDevice::erase(bd_addr_t addr, bd_size_t size)
+{
+    MBED_ASSERT(is_valid_erase(addr, size));
+    // TODO assert on programming unerased blocks
+
+    return 0;
+}
+
+bool RomRamBlockDevice::isRomAddress(const uint8_t *address) {
+    if (((uint32_t)address >= _rom_start)
+     && ((uint32_t)address <= (_rom_end - _erase_size + 1))) {
+        return true;
+    }
+    return false;
+}
+