Satellite Observers Workbench. NOT yet complete, just published for forum posters to \"cherry pick\" pieces of code as requiered as an example.
Diff: flash/flash.c
- Revision:
- 0:0a841b89d614
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/flash/flash.c Mon Oct 11 10:34:55 2010 +0000 @@ -0,0 +1,112 @@ +/**************************************************************************** + * Copyright 2010 Andy Kirkham, Stellar Technologies Ltd + * + * This file is part of the Satellite Observers Workbench (SOWB). + * + * SOWB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * SOWB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with SOWB. If not, see <http://www.gnu.org/licenses/>. + * + * $Id: main.cpp 5 2010-07-12 20:51:11Z ajk $ + * + ***************************************************************************/ + +#include "sowb.h" +#include "debug.h" +#include "ssp0.h" +#include "gpio.h" +#include "flash.h" +#include "user.h" + +extern bool sector_erase_in_progress; +extern bool page_write_in_progress; + +char flash_buffer[2][FLASH_PAGE_SIZE]; +int current_buffer; +unsigned int flash_address; + +/** flash_init + */ +void flash_init(void) { + + /* Initialise the SSP0 to talk to the flash device. */ + SSP0_init(); + + DEBUG_INIT_START; + + /* Clear out the page buffers. */ + memset(flash_buffer, 0, 2 * FLASH_PAGE_SIZE); + + /* Default the buffer in use. */ + current_buffer = 0; + + /* Default pointer set-up. */ + flash_address = 0; + + /* Prime our buffers for expected future access. */ + flash_read_page(0, flash_buffer[0], true); + flash_read_page(1, flash_buffer[1], true); + + /* Although not part of the flash system, SOWB includes + a 25AA02E48 device from Microchip that holds a globally + unique 48bit (6byte) MAC address. We use this for the + SOWB "STL authentic product" serial number and in future + may be used as the ethernet MAC address if we ever write + code to support Ethernet. This device is also connected + to SSP1 and so we'll _init() it here now. */ + //_25AA02E48_init(); + + DEBUG_INIT_END; +} + +/** flash_process + */ +void flash_process(void) { + /* Currently does nothing. */ +} + +/** flash_getc + */ +char flash_getc(bool peek) { + char c; + + /* Flash being deleted, undefined memory. */ + if (sector_erase_in_progress) return 0xFF; + + /* Wait for any page loads to complete. */ + while (page_write_in_progress) user_call_process(); + + /* Get the character from the internal buffer. */ + c = flash_buffer[current_buffer][flash_address]; + + /* If this is just a peek then return the character without + incrementing the memory pointers etc etc. */ + if (peek) return c; + + /* Inc the address pointer and load a new page if needed. Note, + we load the page in background using DMA. */ + flash_address++; + if ((flash_address & 0xFF) == 0) { + flash_read_page(current_buffer >> 8, flash_buffer[current_buffer], false); + current_buffer = current_buffer ? 0 : 1; + } + + return c; +} + +/** flash_seek + */ +void flash_seek(unsigned int addr) { + flash_read_page((addr >> 8) + 0, flash_buffer[0], true); + flash_read_page((addr >> 8) + 1, flash_buffer[1], true); + flash_address = addr; +}