palacios/src/devices/cga.c

   1 /*
   2  * This file is part of the Palacios Virtual Machine Monitor developed
   3  * by the V3VEE Project with funding from the United States National
   4  * Science Foundation and the Department of Energy.
   5  *
   6  * The V3VEE Project is a joint project between Northwestern University
   7  * and the University of New Mexico.  You can find out more at
   8  * http://www.v3vee.org
   9  *
  10  * Copyright (c) 2009, Robert Deloatch <rtdeloatch@gmail.com>
  11  * Copyright (c) 2009, Steven Jaconette <stevenjaconette2007@u.northwestern.edu>
  12  * Copyright (c) 2009, The V3VEE Project <http://www.v3vee.org>
  13  * All rights reserved.
  14  *
  15  * Author: Robdert Deloatch <rtdeloatch@gmail.com>
  16  *         Steven Jaconette <stevenjaconette2007@u.northwestern.edu>
  17  *
  18  * This is free software.  You are permitted to use,
  19  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
  20  */
  21
  22 #include <palacios/vmm.h>
  23 #include <palacios/vmm_dev_mgr.h>
  24 #include <palacios/vmm_emulator.h>
  25 #include <palacios/vm_guest_mem.h>
  26
  27 #include <devices/console.h>
  28
  29
  30
  31
  32 #ifndef DEBUG_CGA
  33 #undef PrintDebug
  34 #define PrintDebug(fmt, args...)
  35 #endif
  36
  37
  38 #define START_ADDR 0xB8000
  39 #define END_ADDR 0xC0000
  40
  41 #define FRAMEBUF_SIZE (END_ADDR - START_ADDR)
  42 #define SCREEN_SIZE 4000
  43
  44 #define BASE_CGA_PORT 0x3B0
  45
  46 #define NUM_COLS 80
  47 #define NUM_ROWS 25
  48 #define BYTES_PER_ROW (NUM_COLS * 2)
  49 #define BYTES_PER_COL 2
  50
  51
  52 struct video_internal {
  53     uint8_t * framebuf;
  54
  55     // These store the values for unhandled ports, in case of a read op
  56     uint8_t port_store[44];
  57
  58
  59     uint8_t crtc_index_reg;          // io port 3D4
  60     uint8_t crtc_data_regs[25];      // io port 3D5
  61
  62     /* IMPORTANT: These are column offsets _NOT_ byte offsets */
  63     uint16_t screen_offset; // relative to the framebuffer
  64     uint16_t cursor_offset; // relative to the framebuffer
  65     /* ** */
  66
  67     // updating the screen offset is not atomic,
  68     // so we need a temp variable to hold the partial update
  69     uint16_t tmp_screen_offset;
  70
  71
  72     uint8_t passthrough;
  73
  74
  75     struct v3_console_ops * ops;
  76     void * private_data;
  77
  78
  79
  80 };
  81
  82
  83
  84
  85 static void passthrough_in(uint16_t port, void * src, uint_t length) {
  86     switch (length) {
  87         case 1:
  88             *(uint8_t *)src = v3_inb(port);
  89             break;
  90         case 2:
  91             *(uint16_t *)src = v3_inw(port);
  92             break;
  93         case 4:
  94             *(uint32_t *)src = v3_indw(port);
  95             break;
  96         default:
  97             break;
  98     }
  99 }
 100
 101
 102 static void passthrough_out(uint16_t port, void * src, uint_t length) {
 103     switch (length) {
 104         case 1:
 105             v3_outb(port, *(uint8_t *)src);
 106             break;
 107         case 2:
 108             v3_outw(port, *(uint16_t *)src);
 109             break;
 110         case 4:
 111             v3_outdw(port, *(uint32_t *)src);
 112             break;
 113         default:
 114             break;
 115     }
 116 }
 117
 118 static int video_write_mem(addr_t guest_addr, void * dest, uint_t length, void * priv_data) {
 119     struct vm_device * dev = (struct vm_device *)priv_data;
 120     struct video_internal * state = (struct video_internal *)dev->private_data;
 121     uint_t fb_offset = guest_addr - START_ADDR;
 122     uint_t screen_byte_offset = state->screen_offset * BYTES_PER_COL;
 123     uint_t screen_length;
 124
 125     PrintDebug("Guest address: %p length = %d, fb_offset=%d, screen_offset=%d\n",
 126                (void *)guest_addr, length, fb_offset, screen_byte_offset);
 127
 128     if (state->passthrough) {
 129         memcpy(state->framebuf + fb_offset, V3_VAddr((void *)guest_addr), length);
 130     }
 131
 132     if ((fb_offset >= screen_byte_offset) && (fb_offset < (screen_byte_offset + SCREEN_SIZE))) {
 133         uint_t screen_pos = fb_offset - screen_byte_offset;
 134         uint_t x = (screen_pos % BYTES_PER_ROW) / BYTES_PER_COL;
 135         uint_t y = screen_pos / BYTES_PER_ROW;
 136         PrintDebug("Sending Screen update\n");
 137
 138         if (state->ops) {
 139             PrintDebug("\tcalling update_screen()\n");
 140
 141             /* avoid updates past end of screen */
 142             screen_length = SCREEN_SIZE - screen_byte_offset;
 143             if (screen_length > length) screen_length = length;
 144             state->ops->update_screen(x, y, screen_length, state->private_data);
 145         }
 146     }
 147
 148     return length;
 149 }
 150
 151 static int video_read_port(uint16_t port, void * dest, uint_t length, struct vm_device * dev) {
 152     struct video_internal * video_state = (struct video_internal *)dev->private_data;
 153
 154
 155     PrintDebug("Video: Read port 0x%x\n", port);
 156
 157     if (video_state->passthrough) {
 158         passthrough_in(port, dest, length);
 159     }
 160
 161     return length;
 162 }
 163
 164
 165
 166 static int video_write_port(uint16_t port, void * src, uint_t length, struct vm_device * dev) {
 167     struct video_internal * video_state = (struct video_internal *)dev->private_data;
 168
 169
 170     PrintDebug("Video: write port 0x%x...\n", port);
 171
 172     if (video_state->passthrough) {
 173         passthrough_out(port, src, length);
 174     }
 175
 176     return length;
 177 }
 178
 179
 180
 181 static int crtc_data_write(uint16_t port, void * src, uint_t length, struct vm_device * dev) {
 182     struct video_internal * video_state = (struct video_internal *)dev->private_data;
 183     uint8_t val = *(uint8_t *)src;
 184     uint_t index = video_state->crtc_index_reg;
 185
 186     if (length != 1) {
 187         PrintError("Invalid write length for port 0x%x\n", port);
 188         return -1;
 189     }
 190
 191     PrintDebug("Video: write on port 0x%x... (val=0x%x)\n", port, val);
 192
 193     video_state->crtc_data_regs[index] = val;
 194
 195     switch (index) {
 196         case 0x0c: { // scroll high byte
 197             uint16_t tmp_val = val;
 198             video_state->tmp_screen_offset = ((tmp_val << 8) & 0xff00);
 199             break;
 200         }
 201         case 0x0d: {  // Scroll low byte
 202             int diff = 0;
 203
 204             video_state->tmp_screen_offset += val;
 205             diff = (video_state->tmp_screen_offset - video_state->screen_offset) / NUM_COLS;
 206
 207             // Update the true offset value
 208             video_state->screen_offset = video_state->tmp_screen_offset;
 209             video_state->tmp_screen_offset = 0;
 210
 211             PrintDebug("Scroll lines = %d, new screen offset=%d\n",
 212                        diff, video_state->screen_offset * BYTES_PER_COL);
 213
 214             if (video_state->ops) {
 215                 if (video_state->ops->scroll(diff, video_state->private_data) == -1) {
 216                     PrintError("Error sending scroll event\n");
 217                     return -1;
 218                 }
 219             }
 220             break;
 221         }
 222         case 0x0E: {  // Cursor adjustment High byte
 223             uint16_t tmp_val = val;
 224             video_state->cursor_offset = ((tmp_val << 8) & 0xff00);
 225
 226             break;
 227         }
 228         case 0x0F: { // cursor adjustment low byte
 229             uint_t x = 0;
 230             uint_t y = 0;
 231
 232             video_state->cursor_offset += val;
 233
 234             x = video_state->cursor_offset % NUM_COLS;
 235             y = (video_state->cursor_offset - video_state->screen_offset) / NUM_COLS;
 236
 237             PrintDebug("New Cursor Location; X=%d Y=%d\n", x, y);
 238
 239             if (video_state->ops) {
 240                 if (video_state->ops->update_cursor(x, y, video_state->private_data) == -1) {
 241                     PrintError("Error updating cursor\n");
 242                     return -1;
 243                 }
 244             }
 245
 246             break;
 247         }
 248         default:
 249             break;
 250     }
 251
 252     if (video_state->passthrough) {
 253         passthrough_out(port, src, length);
 254     }
 255
 256     return length;
 257 }
 258
 259
 260 static int crtc_index_write(uint16_t port, void * src, uint_t length, struct vm_device * dev) {
 261     struct video_internal * video_state = (struct video_internal *)dev->private_data;
 262
 263     if (length > 2) {
 264         PrintError("Invalid write length for crtc index register port: %d (0x%x)\n",
 265                    port, port);
 266         return -1;
 267     }
 268
 269
 270     video_state->crtc_index_reg = *(uint8_t *)src;
 271
 272     // Only do the passthrough IO for the first byte
 273     // the second byte will be done in the data register handler
 274     if (video_state->passthrough) {
 275         passthrough_out(port, src, 1);
 276     }
 277
 278     if (length == 2) {
 279         if (crtc_data_write(port + 1, src + 1, length - 1, dev) != (length - 1)) {
 280             PrintError("could not handle implicit crtc data write\n");
 281             return -1;
 282         }
 283     }
 284
 285     return length;
 286 }
 287
 288
 289
 290 int v3_cons_get_fb(struct vm_device * frontend_dev, uint8_t * dst, uint_t offset, uint_t length) {
 291     struct video_internal * state = (struct video_internal *)frontend_dev->private_data;
 292     uint_t screen_byte_offset = state->screen_offset * BYTES_PER_COL;
 293
 294     PrintDebug("Getting framebuffer for screen; framebuf=%p, screen_offset=%d, offset=%d, length=%d\n",
 295                state->framebuf, screen_byte_offset, offset, length);
 296
 297     memcpy(dst, state->framebuf + screen_byte_offset + offset, length);
 298
 299     return 0;
 300 }
 301
 302
 303
 304 static int free_device(struct vm_device * dev) {
 305     v3_unhook_mem(dev->vm, START_ADDR);
 306     return 0;
 307 }
 308
 309
 310
 311 static struct v3_device_ops dev_ops = {
 312     .free = free_device,
 313     .reset = NULL,
 314     .start = NULL,
 315     .stop = NULL,
 316 };
 317
 318 static int cga_init(struct guest_info * vm, v3_cfg_tree_t * cfg) {
 319     struct video_internal * video_state = (struct video_internal *)V3_Malloc(sizeof(struct video_internal));
 320     addr_t frame_buf_pa = 0;
 321     int enable_passthrough = 0;
 322     char * name = v3_cfg_val(cfg, "name");
 323
 324     enable_passthrough = (strcasecmp(v3_cfg_val(cfg, "passthrough"), "enable") == 0) ? 1 : 0;
 325
 326     PrintDebug("video: init_device\n");
 327
 328     struct vm_device * dev = v3_allocate_device(name, &dev_ops, video_state);
 329
 330     if (v3_attach_device(vm, dev) == -1) {
 331         PrintError("Could not attach device %s\n", name);
 332         return -1;
 333     }
 334
 335     frame_buf_pa = (addr_t)V3_AllocPages(FRAMEBUF_SIZE / 4096);
 336
 337     video_state->framebuf = V3_VAddr((void *)frame_buf_pa);
 338     memset(video_state->framebuf, 0, FRAMEBUF_SIZE);
 339
 340     PrintDebug("PA of array: %p\n", (void *)frame_buf_pa);
 341
 342     video_state->passthrough = enable_passthrough;
 343
 344     video_state->ops = NULL;
 345     video_state->private_data = NULL;
 346
 347     if (enable_passthrough) {
 348         PrintDebug("Enabling CGA Passthrough\n");
 349
 350         if (v3_hook_write_mem(vm, START_ADDR, END_ADDR, START_ADDR, &video_write_mem, dev) == -1) {
 351             PrintDebug("\n\nVideo Hook failed.\n\n");
 352         }
 353     } else {
 354         if (v3_hook_write_mem(vm, START_ADDR, END_ADDR, frame_buf_pa, &video_write_mem, dev) == -1) {
 355             PrintDebug("\n\nVideo Hook failed.\n\n");
 356         }
 357     }
 358
 359
 360     v3_dev_hook_io(dev, 0x3b0, &video_read_port, &video_write_port);
 361     v3_dev_hook_io(dev, 0x3b1, &video_read_port, &video_write_port);
 362     v3_dev_hook_io(dev, 0x3b2, &video_read_port, &video_write_port);
 363     v3_dev_hook_io(dev, 0x3b3, &video_read_port, &video_write_port);
 364     v3_dev_hook_io(dev, 0x3b4, &video_read_port, &video_write_port);
 365     v3_dev_hook_io(dev, 0x3b5, &video_read_port, &video_write_port);
 366     v3_dev_hook_io(dev, 0x3b6, &video_read_port, &video_write_port);
 367     v3_dev_hook_io(dev, 0x3b7, &video_read_port, &video_write_port);
 368     v3_dev_hook_io(dev, 0x3b8, &video_read_port, &video_write_port);
 369     v3_dev_hook_io(dev, 0x3b9, &video_read_port, &video_write_port);
 370     v3_dev_hook_io(dev, 0x3ba, &video_read_port, &video_write_port);
 371     v3_dev_hook_io(dev, 0x3bb, &video_read_port, &video_write_port);
 372     v3_dev_hook_io(dev, 0x3c0, &video_read_port, &video_write_port);
 373     v3_dev_hook_io(dev, 0x3c1, &video_read_port, &video_write_port);
 374     v3_dev_hook_io(dev, 0x3c2, &video_read_port, &video_write_port);
 375     v3_dev_hook_io(dev, 0x3c3, &video_read_port, &video_write_port);
 376     v3_dev_hook_io(dev, 0x3c4, &video_read_port, &video_write_port);
 377     v3_dev_hook_io(dev, 0x3c5, &video_read_port, &video_write_port);
 378     v3_dev_hook_io(dev, 0x3c6, &video_read_port, &video_write_port);
 379     v3_dev_hook_io(dev, 0x3c7, &video_read_port, &video_write_port);
 380     v3_dev_hook_io(dev, 0x3c8, &video_read_port, &video_write_port);
 381     v3_dev_hook_io(dev, 0x3c9, &video_read_port, &video_write_port);
 382     v3_dev_hook_io(dev, 0x3ca, &video_read_port, &video_write_port);
 383     v3_dev_hook_io(dev, 0x3cb, &video_read_port, &video_write_port);
 384     v3_dev_hook_io(dev, 0x3cc, &video_read_port, &video_write_port);
 385     v3_dev_hook_io(dev, 0x3cd, &video_read_port, &video_write_port);
 386     v3_dev_hook_io(dev, 0x3ce, &video_read_port, &video_write_port);
 387     v3_dev_hook_io(dev, 0x3cf, &video_read_port, &video_write_port);
 388     v3_dev_hook_io(dev, 0x3d0, &video_read_port, &video_write_port);
 389     v3_dev_hook_io(dev, 0x3d1, &video_read_port, &video_write_port);
 390     v3_dev_hook_io(dev, 0x3d2, &video_read_port, &video_write_port);
 391     v3_dev_hook_io(dev, 0x3d3, &video_read_port, &video_write_port);
 392     v3_dev_hook_io(dev, 0x3d4, &video_read_port, &crtc_index_write);
 393     v3_dev_hook_io(dev, 0x3d5, &video_read_port, &crtc_data_write);
 394     v3_dev_hook_io(dev, 0x3d6, &video_read_port, &video_write_port);
 395     v3_dev_hook_io(dev, 0x3d7, &video_read_port, &video_write_port);
 396     v3_dev_hook_io(dev, 0x3d8, &video_read_port, &video_write_port);
 397     v3_dev_hook_io(dev, 0x3d9, &video_read_port, &video_write_port);
 398     v3_dev_hook_io(dev, 0x3da, &video_read_port, &video_write_port);
 399     v3_dev_hook_io(dev, 0x3db, &video_read_port, &video_write_port);
 400     v3_dev_hook_io(dev, 0x3dc, &video_read_port, &video_write_port);
 401     v3_dev_hook_io(dev, 0x3dd, &video_read_port, &video_write_port);
 402     v3_dev_hook_io(dev, 0x3de, &video_read_port, &video_write_port);
 403     v3_dev_hook_io(dev, 0x3df, &video_read_port, &video_write_port);
 404
 405
 406     return 0;
 407 }
 408
 409 device_register("CGA_VIDEO", cga_init);
 410
 411
 412 int v3_console_register_cga(struct vm_device * cga_dev, struct v3_console_ops * ops, void * private_data) {
 413     struct video_internal * video_state = (struct video_internal *)cga_dev->private_data;
 414
 415     video_state->ops = ops;
 416     video_state->private_data = private_data;
 417
 418     return 0;
 419 }