/* setup_x_magic:
* To make sure that things will go on working properly even if a few
* bits of code don't know about mode-X screens, we do special magic
* inside the bank switch functions to emulate a linear image surface.
* Whenever someone tries to access the screen directly, these routines
* copy the planar image into a temporary buffer, let the client write
* there, and then automatically refresh the screen with the updated
* graphics. Very slow, but it makes 100% sure that everything will work.
*/
static void setup_x_magic(BITMAP *b)
{
#ifdef ALLEGRO_DOS
/* DOS buffer has to go in conventional memory */
int seg = __dpmi_allocate_dos_memory((b->w+15)/16, &magic_sel);
if (seg > 0)
_x_magic_buffer_addr = seg*16;
else
_x_magic_buffer_addr = 0;
#else
/* other platforms can put the buffer wherever they like */
_x_magic_buffer_addr = (unsigned long)_AL_MALLOC(b->w);
#endif
_x_magic_screen_addr = 0;
_x_magic_screen_width = 0;
LOCK_VARIABLE(_x_magic_buffer_addr);
LOCK_VARIABLE(_x_magic_screen_addr);
LOCK_VARIABLE(_x_magic_screen_width);
LOCK_FUNCTION(_x_bank_switch);
b->write_bank = b->read_bank = _x_bank_switch;
}
int emm_init(void)
{
/* TODO: check EMM presence */
/* allocate 1 para for page map array */
rmseg = __dpmi_allocate_dos_memory(1, &rmsel);
if (rmseg == -1)
return -1;
__dpmi_get_segment_base_address(rmsel, &rmaddr);
return 0;
}
/*
* Called from setup_pkt_inf() in pcpkt.c
*/
static DWORD setup_pkt_inf_fast (void)
{
/* Allocate space for asmpkt_inf, temp area, pkt-stub and Tx buffer.
*/
DWORD rdata_size = PKT_TMP();
size_t stub_size = sizeof(real_stub_array);
#if (DOSX)
rdata_size += PKT_TMP_SIZE + ETH_MAX + 10;
#endif
if (rdata_size >= 64*1024UL)
{
TCP_CONSOLE_MSG (0, ("%s (%u): Development error:\nsize %u too large\n",
__FILE__, __LINE__, (unsigned int)rdata_size));
return (0);
}
if (stub_size < 0xC0)
{
TCP_CONSOLE_MSG (0, ("%s (%u): Development error:\n\"pkt_stub.h\""
" seems truncated (%d bytes)\n",
__FILE__, __LINE__, SIZEOF(real_stub_array)));
return (0);
}
#if (DOSX & DJGPP)
{
int i, seg, sel;
seg = __dpmi_allocate_dos_memory ((rdata_size+15)/16, &sel);
if (seg < 0)
return (0);
_pkt_inf->rm_seg = seg;
_pkt_inf->rm_sel = sel;
rm_base = (_pkt_inf->rm_seg << 4);
for (i = 0; i < (int)rdata_size; i += 4) /* clear area */
POKEL (_pkt_inf->rm_seg, i, 0);
}
#elif (DOSX & DOS4GW)
{
WORD seg, sel;
seg = dpmi_real_malloc (rdata_size, &sel);
if (!seg)
return (0);
_pkt_inf->rm_seg = seg;
_pkt_inf->rm_sel = sel;
rm_base = (_pkt_inf->rm_seg) << 4;
memset ((void*)rm_base, 0, rdata_size);
}
#elif (DOSX & PHARLAP)
{
WORD largest, seg;
int i;
if (_dx_real_alloc ((rdata_size+15)/16, &seg, &largest) != 0)
return (0);
_pkt_inf->rm_seg = seg;
_pkt_inf->rm_sel = 0;
RP_SET (rm_base, 0, _pkt_inf->rm_seg);
for (i = 0; i < (int)rdata_size; i += 4)
POKEL (_pkt_inf->rm_seg, i, 0);
}
#elif (DOSX & X32VM)
{
int i;
rm_base = _x32_real_alloc (rdata_size);
if (!rm_base)
return (0);
_pkt_inf->rm_seg = _x32_real_segment (rm_base);
_pkt_inf->rm_sel = 0;
for (i = 0; i < (int)rdata_size; i += 4)
POKEL (_pkt_inf->rm_seg, i, 0);
}
#elif (DOSX & POWERPAK)
{
WORD seg, sel;
int i;
seg = dpmi_real_malloc ((rdata_size+15)/16, &sel);
if (!seg)
return (0);
_pkt_inf->rm_seg = seg;
_pkt_inf->rm_sel = sel;
RP_SET (rm_base, 0, _pkt_inf->rm_seg);
for (i = 0; i < (int)rdata_size; i += 4)
POKEL (_pkt_inf->rm_seg, i, 0);
}
#elif (DOSX == 0)
{
char _far *buf = _fcalloc (rdata_size, 0);
if (!buf)
return (0);
_pkt_inf->rm_seg = FP_SEG (buf);
rm_base = (DWORD) buf;
}
#else
#error Help!
#endif
pktq_far_init (sizeof(struct pkt_rx_element), RX_BUFS, ASMPKT_INF);
_pkt_inf->pkt_queue.num_buf = RX_BUFS;
return (rm_base);
}
dma_buffer *dma_allocate(unsigned int channel, unsigned int size)
{
int parsize = (size + 15) >> 4; /* size in paragraphs */
int par = 0; /* Real-mode paragraph */
int selector = 0; /* Protected-mode selector */
int mask = channel <= 3 ? 0xfff : 0x1fff; /* Alignment mask in para. */
int allocsize = parsize; /* Allocated size in paragraphs */
int count; /* Try count */
int bound = 0; /* Nearest bound address */
int maxsize; /* Maximal possible block size */
dma_buffer *buffer = NULL;
__dpmi_meminfo buff_info, struct_info;
if (!dma_initialize())
return NULL;
/* Loop until we'll get a properly aligned memory block */
for (count = 8; count; count--) {
int resize = (selector != 0);
/* Try first to resize (possibly previously) allocated block */
if (resize) {
maxsize = (bound + parsize) - par;
if (maxsize > parsize * 2)
maxsize = parsize * 2;
if (maxsize == allocsize)
resize = 0;
else {
allocsize = maxsize;
/* BUG WARNING: there is an error in dpmi.h DJGPP 2.01 library:
the order of "selector" and "alloc size" should be
reversed */
if (__dpmi_resize_dos_memory(allocsize, selector, &maxsize) !=
0) resize = 0;
}
}
if (!resize) {
if (selector)
__dpmi_free_dos_memory(selector), selector = 0;
par = __dpmi_allocate_dos_memory(allocsize, &selector);
}
if ((par == 0) || (par == -1))
goto exit;
/* If memory block contains a properly aligned portion, quit loop */
bound = (par + mask + 1) & ~mask;
if (par + parsize <= bound)
break;
if (bound + parsize <= par + allocsize) {
par = bound;
break;
}
}
if (!count) {
__dpmi_free_dos_memory(selector);
goto exit;
}
buffer = malloc(sizeof(dma_buffer));
buffer->linear = (void *)(__djgpp_conventional_base + bound * 16);
buffer->physical = bound * 16;
buffer->size = parsize * 16;
buffer->selector = selector;
buffer->channel = channel;
buff_info.address = buffer->physical;
buff_info.size = buffer->size;
/*
Don't pay attention to return code since under plain DOS it often
returns error (at least under HIMEM/CWSDPMI and EMM386/DPMI)
*/
__dpmi_lock_linear_region(&buff_info);
/* Lock the DMA buffer control structure as well */
struct_info.address = __djgpp_base_address + (unsigned long)buffer;
struct_info.size = sizeof(dma_buffer);
if (__dpmi_lock_linear_region(&struct_info)) {
__dpmi_unlock_linear_region(&buff_info);
__dpmi_free_dos_memory(selector);
free(buffer);
buffer = NULL;
goto exit;
}
exit:
if (buffer)
__buffer_count++;
else if (--__buffer_count == 0)
dma_finalize();
return buffer;
}
