56 lines
1.7 KiB
C
56 lines
1.7 KiB
C
/*
|
|
* Copyright (c) 2024 Scott Duensing, scott@kangaroopunch.com
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
|
|
#include "dma.h"
|
|
|
|
|
|
char error;
|
|
|
|
|
|
static void dmaWait(void);
|
|
|
|
|
|
void dmaFill(uint32_t start, uint32_t length, byte value) {
|
|
byte mmu = PEEK(MMU_IO_CTRL); // Get current MMU state.
|
|
|
|
POKE(MMU_IO_CTRL, MMU_IO_PAGE_0); // Swap I/O page 0 into bank 6.
|
|
|
|
POKE(DMA_CTRL, DMA_CTRL_FILL | DMA_CTRL_ENABLE);
|
|
POKE(DMA_FILL_VAL, value);
|
|
POKEA(DMA_DST_ADDR, start);
|
|
POKEA(DMA_COUNT, length);
|
|
POKE(DMA_CTRL, DMA_CTRL_FILL | DMA_CTRL_ENABLE | DMA_CTRL_START);
|
|
|
|
dmaWait();
|
|
|
|
POKE(MMU_IO_CTRL, mmu); // Restore MMU state.
|
|
}
|
|
|
|
|
|
static void dmaWait(void) {
|
|
while (PEEK(DMA_STATUS) & DMA_STAT_BUSY)
|
|
// Spin our wheels.
|
|
;
|
|
|
|
POKE(DMA_CTRL, 0);
|
|
}
|