static void
ensure_empty_mapping( void )
{
int i;
libspectrum_byte *empty_chunk;
if( empty_mapping_allocated ) return;
empty_chunk = memory_pool_allocate_persistent( 0x4000, 1 );
memset( empty_chunk, 0xff, 0x4000 );
for( i = 0; i < MEMORY_PAGES_IN_16K; i++ ) {
memory_page *page = &empty_mapping[i];
page->page = empty_chunk + i * MEMORY_PAGE_SIZE;
page->writable = 0;
page->contended = 0;
page->source = memory_source_none;
}
empty_mapping_allocated = 1;
}
static void
spectranet_activate( void )
{
if( !spectranet_memory_allocated ) {
int i, j;
libspectrum_byte *rom;
libspectrum_byte *ram;
libspectrum_byte *fake_bank =
memory_pool_allocate_persistent( 0x1000, 1 );
memset( fake_bank, 0xff, 0x1000 );
/* Start of by mapping the fake data in everywhere */
for( i = 0; i < SPECTRANET_PAGES; i++ )
for( j = 0; j < MEMORY_PAGES_IN_4K; j++ ) {
memory_page *page = &spectranet_full_map[i * MEMORY_PAGES_IN_4K + j];
page->writable = 0;
page->contended = 0;
page->source = spectranet_source;
page->save_to_snapshot = 0;
page->page_num = i;
page->offset = j * MEMORY_PAGE_SIZE;
page->page = fake_bank + page->offset;
}
/* Pages 0x00 to 0x1f are the flash ROM */
rom = memory_pool_allocate_persistent( SPECTRANET_ROM_LENGTH, 1 );
memset( rom, 0xff, SPECTRANET_ROM_LENGTH );
for( i = 0; i < SPECTRANET_ROM_LENGTH / SPECTRANET_PAGE_LENGTH; i++ ) {
int base = (SPECTRANET_ROM_BASE + i) * MEMORY_PAGES_IN_4K;
for( j = 0; j < MEMORY_PAGES_IN_4K; j++ ) {
memory_page *page = &spectranet_full_map[base + j];
page->page = rom + (i * MEMORY_PAGES_IN_4K + j) * MEMORY_PAGE_SIZE;
}
}
flash_am29f010_init( flash_rom, rom );
/* Pages 0x40 to 0x47 are the W5100 registers - handled in readbyte()
and writebyte() */
/* Pages 0xc0 to 0xff are the RAM */
ram = memory_pool_allocate_persistent( SPECTRANET_RAM_LENGTH, 1 );
for( i = 0; i < SPECTRANET_RAM_LENGTH / SPECTRANET_PAGE_LENGTH; i++ ) {
int base = (SPECTRANET_RAM_BASE + i) * MEMORY_PAGES_IN_4K;
for( j = 0; j < MEMORY_PAGES_IN_4K; j++ ) {
memory_page *page = &spectranet_full_map[base + j];
page->writable = 1;
page->page = ram + (i * MEMORY_PAGES_IN_4K + j) * MEMORY_PAGE_SIZE;
}
}
spectranet_memory_allocated = 1;
spectranet_map_page( 0, 0x00 );
spectranet_map_page( 3, 0xc0 );
spectranet_hard_reset();
}
}
/* Allocate some memory from the pool */
libspectrum_byte*
memory_pool_allocate( size_t length )
{
return memory_pool_allocate_persistent( length, 0 );
}