| // Standard VGA driver code |
| // |
| // Copyright (C) 2009-2024 Kevin O'Connor <kevin@koconnor.net> |
| // Copyright (C) 2001-2008 the LGPL VGABios developers Team |
| // |
| // This file may be distributed under the terms of the GNU LGPLv3 license. |
| |
| #include "biosvar.h" // GET_GLOBAL |
| #include "farptr.h" // SET_FARVAR |
| #include "stdvga.h" // stdvga_setup |
| #include "string.h" // memset_far |
| #include "vgabios.h" // struct vgamode_s |
| #include "vgautil.h" // stdvga_attr_write |
| #include "x86.h" // outb |
| |
| |
| /**************************************************************** |
| * Attribute control |
| ****************************************************************/ |
| |
| // Emulate CGA background setting via VGA palette index registers |
| void |
| stdvga_set_cga_background_color(u8 color) |
| { |
| // Set the background color (via palette index 0) |
| u8 v1 = color & 0x0f; |
| if (v1 & 0x08) |
| v1 += 0x08; |
| stdvga_attr_write(0x00, v1); |
| |
| // Dim/brighten foreground (see pal_cga[] in stdvgamodes.c) |
| int i; |
| for (i = 1; i < 4; i++) |
| stdvga_attr_mask(i, 0x10, color & 0x10); |
| } |
| |
| // Emulate CGA palette setting by altering VGA palette index registers |
| void |
| stdvga_set_cga_palette(u8 palid) |
| { |
| // Switch foreground colors (see pal_cga[] in stdvgamodes.c) |
| int i; |
| for (i = 1; i < 4; i++) |
| stdvga_attr_mask(i, 0x01, palid & 0x01); |
| } |
| |
| // Set the VGA palette index register for the "overscan" area |
| void |
| stdvga_set_overscan_border_color(u8 color) |
| { |
| stdvga_attr_write(0x11, color); |
| } |
| |
| // Get the VGA palette index register for the "overscan" area |
| u8 |
| stdvga_get_overscan_border_color(void) |
| { |
| return stdvga_attr_read(0x11); |
| } |
| |
| // Set the VGA palette index registers |
| void |
| stdvga_set_all_palette_reg(u16 seg, u8 *data_far) |
| { |
| // Set palette indexes (offset into DAC colors) |
| int i; |
| for (i = 0; i < 0x10; i++) { |
| stdvga_attr_write(i, GET_FARVAR(seg, *data_far)); |
| data_far++; |
| } |
| // Set "overscan" palette index (offset into DAC colors) |
| stdvga_attr_write(0x11, GET_FARVAR(seg, *data_far)); |
| } |
| |
| // Get the VGA palette index registers |
| void |
| stdvga_get_all_palette_reg(u16 seg, u8 *data_far) |
| { |
| int i; |
| for (i = 0; i < 0x10; i++) { |
| SET_FARVAR(seg, *data_far, stdvga_attr_read(i)); |
| data_far++; |
| } |
| SET_FARVAR(seg, *data_far, stdvga_attr_read(0x11)); |
| } |
| |
| // Set blinking mode (when enabled, palette index bit 0x08 indicates blinking) |
| void |
| stdvga_set_palette_blinking(u8 enable_blink) |
| { |
| stdvga_attr_mask(0x10, 0x08, (enable_blink & 0x01) << 3); |
| } |
| |
| // Select 4-bit or 6-bit palette indexes (for "page" switching of colors) |
| void |
| stdvga_set_palette_pagesize(u8 pal_pagesize) |
| { |
| stdvga_attr_mask(0x10, 0x80, pal_pagesize << 7); |
| } |
| |
| // Set palette index offset (enables color switching via "pages") |
| void |
| stdvga_set_palette_page(u8 pal_page) |
| { |
| // Check if using 4-bit or 6-bit "palette index pages" |
| u8 val = stdvga_attr_read(0x10); |
| if (!(val & 0x80)) |
| pal_page <<= 2; |
| // select page |
| pal_page &= 0x0f; |
| stdvga_attr_write(0x14, pal_page); |
| } |
| |
| // Report current palette index pagesize and current page |
| void |
| stdvga_get_palette_page(u8 *pal_pagesize, u8 *pal_page) |
| { |
| u8 val1 = stdvga_attr_read(0x10) >> 7; |
| u8 val2 = stdvga_attr_read(0x14) & 0x0f; |
| if (!(val1 & 0x01)) |
| val2 >>= 2; |
| *pal_pagesize = val1; |
| *pal_page = val2; |
| } |
| |
| |
| /**************************************************************** |
| * DAC control |
| ****************************************************************/ |
| |
| // Convert all loaded colors to shades of gray |
| void |
| stdvga_perform_gray_scale_summing(u16 start, u16 count) |
| { |
| stdvga_attrindex_write(0x00); |
| int i; |
| for (i = start; i < start+count; i++) { |
| u8 rgb[3]; |
| stdvga_dac_read(GET_SEG(SS), rgb, i, 1); |
| |
| // intensity = ( 0.3 * Red ) + ( 0.59 * Green ) + ( 0.11 * Blue ) |
| u16 intensity = ((77 * rgb[0] + 151 * rgb[1] + 28 * rgb[2]) + 0x80) >> 8; |
| if (intensity > 0x3f) |
| intensity = 0x3f; |
| rgb[0] = rgb[1] = rgb[2] = intensity; |
| |
| stdvga_dac_write(GET_SEG(SS), rgb, i, 1); |
| } |
| stdvga_attrindex_write(0x20); |
| } |
| |
| |
| /**************************************************************** |
| * Memory control |
| ****************************************************************/ |
| |
| // Enable reads and writes to the given "plane" when in planar4 mode. |
| void |
| stdvga_planar4_plane(int plane) |
| { |
| if (plane < 0) { |
| // Return to default mode (read plane0, write all planes) |
| stdvga_sequ_write(0x02, 0x0f); |
| stdvga_grdc_write(0x04, 0); |
| } else { |
| stdvga_sequ_write(0x02, 1<<plane); |
| stdvga_grdc_write(0x04, plane); |
| } |
| } |
| |
| |
| /**************************************************************** |
| * Font loading |
| ****************************************************************/ |
| |
| // Set the video memory location of the start of character fonts |
| void |
| stdvga_set_font_location(u8 spec) |
| { |
| stdvga_sequ_write(0x03, spec); |
| } |
| |
| static void |
| get_font_access(void) |
| { |
| stdvga_sequ_write(0x00, 0x01); |
| stdvga_sequ_write(0x02, 0x04); |
| stdvga_sequ_write(0x04, 0x07); |
| stdvga_sequ_write(0x00, 0x03); |
| stdvga_grdc_write(0x04, 0x02); |
| stdvga_grdc_write(0x05, 0x00); |
| stdvga_grdc_write(0x06, 0x04); |
| } |
| |
| static void |
| release_font_access(void) |
| { |
| stdvga_sequ_write(0x00, 0x01); |
| stdvga_sequ_write(0x02, 0x03); |
| stdvga_sequ_write(0x04, 0x03); |
| stdvga_sequ_write(0x00, 0x03); |
| u16 v = (stdvga_misc_read() & 0x01) ? 0x0e : 0x0a; |
| stdvga_grdc_write(0x06, v); |
| stdvga_grdc_write(0x04, 0x00); |
| stdvga_grdc_write(0x05, 0x10); |
| } |
| |
| void |
| stdvga_load_font(u16 seg, void *src_far, u16 count |
| , u16 start, u8 destflags, u8 fontsize) |
| { |
| get_font_access(); |
| u16 blockaddr = ((destflags & 0x03) << 14) + ((destflags & 0x04) << 11); |
| void *dest_far = (void*)(blockaddr + start*32); |
| u16 i; |
| for (i = 0; i < count; i++) |
| memcpy_far(SEG_GRAPH, dest_far + i*32 |
| , seg, src_far + i*fontsize, fontsize); |
| release_font_access(); |
| } |
| |
| |
| /**************************************************************** |
| * CRTC registers |
| ****************************************************************/ |
| |
| // Return the IO port used to access the CRTC register |
| u16 |
| stdvga_get_crtc(void) |
| { |
| if (stdvga_misc_read() & 1) |
| return VGAREG_VGA_CRTC_ADDRESS; |
| return VGAREG_MDA_CRTC_ADDRESS; |
| } |
| |
| // Ratio between system visible framebuffer ram and the actual videoram used. |
| int |
| stdvga_vram_ratio(struct vgamode_s *vmode_g) |
| { |
| switch (GET_GLOBAL(vmode_g->memmodel)) { |
| case MM_TEXT: |
| return 2; |
| case MM_CGA: |
| return 4 / GET_GLOBAL(vmode_g->depth); |
| case MM_PLANAR: |
| return 4; |
| default: |
| return 1; |
| } |
| } |
| |
| // Set cursor shape (when in text mode) |
| void |
| stdvga_set_cursor_shape(u16 cursor_type) |
| { |
| u16 crtc_addr = stdvga_get_crtc(); |
| stdvga_crtc_write(crtc_addr, 0x0a, cursor_type >> 8); |
| stdvga_crtc_write(crtc_addr, 0x0b, cursor_type); |
| } |
| |
| // Set the position of the text cursor (as offset into system framebuffer) |
| void |
| stdvga_set_cursor_pos(int address) |
| { |
| u16 crtc_addr = stdvga_get_crtc(); |
| address /= 2; // Assume we're in text mode. |
| stdvga_crtc_write(crtc_addr, 0x0e, address >> 8); |
| stdvga_crtc_write(crtc_addr, 0x0f, address); |
| } |
| |
| // Set the character height (when in text mode) |
| void |
| stdvga_set_character_height(u8 lines) |
| { |
| stdvga_crtc_mask(stdvga_get_crtc(), 0x09, 0x1f, lines - 1); |
| } |
| |
| // Get vertical screen size (number of horizontal lines in the display) |
| u16 |
| stdvga_get_vertical_size(void) |
| { |
| u16 crtc_addr = stdvga_get_crtc(); |
| u16 vde = stdvga_crtc_read(crtc_addr, 0x12); |
| u8 ovl = stdvga_crtc_read(crtc_addr, 0x07); |
| vde += ((ovl & 0x02) << 7) + ((ovl & 0x40) << 3); |
| return vde + 1; |
| } |
| |
| // Get offset into framebuffer accessible from real-mode 64K segment |
| int |
| stdvga_get_window(struct vgamode_s *curmode_g, int window) |
| { |
| return -1; |
| } |
| |
| // Set offset into framebuffer that is accessible from real-mode 64K |
| // segment (in units of VBE_win_granularity windows) |
| int |
| stdvga_set_window(struct vgamode_s *curmode_g, int window, int val) |
| { |
| // Stdvga does not support changing window offset |
| return -1; |
| } |
| |
| // Minimum framebuffer bytes between each vertical line for given mode |
| int |
| stdvga_minimum_linelength(struct vgamode_s *vmode_g) |
| { |
| return DIV_ROUND_UP(GET_GLOBAL(vmode_g->width) * vga_bpp(vmode_g), 8); |
| } |
| |
| // Return number of framebuffer bytes between start of each vertical line |
| int |
| stdvga_get_linelength(struct vgamode_s *curmode_g) |
| { |
| u8 val = stdvga_crtc_read(stdvga_get_crtc(), 0x13); |
| return val * 8 / stdvga_vram_ratio(curmode_g); |
| } |
| |
| // Set number of framebuffer bytes between start of each vertical line |
| int |
| stdvga_set_linelength(struct vgamode_s *curmode_g, int val) |
| { |
| val = DIV_ROUND_UP(val * stdvga_vram_ratio(curmode_g), 8); |
| stdvga_crtc_write(stdvga_get_crtc(), 0x13, val); |
| return 0; |
| } |
| |
| // Return framebuffer offset of first byte of displayed content |
| int |
| stdvga_get_displaystart(struct vgamode_s *curmode_g) |
| { |
| u16 crtc_addr = stdvga_get_crtc(); |
| int addr = (stdvga_crtc_read(crtc_addr, 0x0c) << 8 |
| | stdvga_crtc_read(crtc_addr, 0x0d)); |
| return addr * 4 / stdvga_vram_ratio(curmode_g); |
| } |
| |
| // Set framebuffer offset of first byte of displayed content |
| int |
| stdvga_set_displaystart(struct vgamode_s *curmode_g, int val) |
| { |
| u16 crtc_addr = stdvga_get_crtc(); |
| val = val * stdvga_vram_ratio(curmode_g) / 4; |
| stdvga_crtc_write(crtc_addr, 0x0c, val >> 8); |
| stdvga_crtc_write(crtc_addr, 0x0d, val); |
| return 0; |
| } |
| |
| // Report if using 8bit per rgb (24bit total) or 6bit per rgb (18bit total) |
| int |
| stdvga_get_dacformat(struct vgamode_s *curmode_g) |
| { |
| return -1; |
| } |
| |
| // Set 8bit per rgb (24bit total) or 6bit per rgb (18bit total) |
| int |
| stdvga_set_dacformat(struct vgamode_s *curmode_g, int val) |
| { |
| // Stdvga only supports 6bits for each color channel |
| return -1; |
| } |
| |
| |
| /**************************************************************** |
| * Save/Restore state |
| ****************************************************************/ |
| |
| struct saveVideoHardware { |
| u8 sequ_index; |
| u8 crtc_index; |
| u8 grdc_index; |
| u8 actl_index; |
| u8 feature; |
| u8 sequ_regs[4]; |
| u8 sequ0; |
| u8 crtc_regs[25]; |
| u8 actl_regs[20]; |
| u8 grdc_regs[9]; |
| u16 crtc_addr; |
| u8 plane_latch[4]; |
| } PACKED; |
| |
| static void |
| stdvga_save_hw_state(u16 seg, struct saveVideoHardware *info) |
| { |
| u16 crtc_addr = stdvga_get_crtc(); |
| SET_FARVAR(seg, info->sequ_index, inb(VGAREG_SEQU_ADDRESS)); |
| SET_FARVAR(seg, info->crtc_index, inb(crtc_addr)); |
| SET_FARVAR(seg, info->grdc_index, inb(VGAREG_GRDC_ADDRESS)); |
| SET_FARVAR(seg, info->actl_index, stdvga_attrindex_read()); |
| SET_FARVAR(seg, info->feature, inb(VGAREG_READ_FEATURE_CTL)); |
| |
| int i; |
| for (i=0; i<4; i++) |
| SET_FARVAR(seg, info->sequ_regs[i], stdvga_sequ_read(i+1)); |
| SET_FARVAR(seg, info->sequ0, stdvga_sequ_read(0)); |
| |
| for (i=0; i<25; i++) |
| SET_FARVAR(seg, info->crtc_regs[i], stdvga_crtc_read(crtc_addr, i)); |
| |
| for (i=0; i<20; i++) |
| SET_FARVAR(seg, info->actl_regs[i], stdvga_attr_read(i)); |
| |
| for (i=0; i<9; i++) |
| SET_FARVAR(seg, info->grdc_regs[i], stdvga_grdc_read(i)); |
| |
| SET_FARVAR(seg, info->crtc_addr, crtc_addr); |
| |
| /* XXX: read plane latches */ |
| for (i=0; i<4; i++) |
| SET_FARVAR(seg, info->plane_latch[i], 0); |
| } |
| |
| static void |
| stdvga_restore_hw_state(u16 seg, struct saveVideoHardware *info) |
| { |
| int i; |
| for (i=0; i<4; i++) |
| stdvga_sequ_write(i+1, GET_FARVAR(seg, info->sequ_regs[i])); |
| stdvga_sequ_write(0x00, GET_FARVAR(seg, info->sequ0)); |
| |
| // Disable CRTC write protection |
| u16 crtc_addr = GET_FARVAR(seg, info->crtc_addr); |
| stdvga_crtc_write(crtc_addr, 0x11, 0x00); |
| // Set CRTC regs |
| for (i=0; i<25; i++) |
| if (i != 0x11) |
| stdvga_crtc_write(crtc_addr, i, GET_FARVAR(seg, info->crtc_regs[i])); |
| // select crtc base address |
| stdvga_misc_mask(0x01, crtc_addr == VGAREG_VGA_CRTC_ADDRESS ? 0x01 : 0x00); |
| |
| // enable write protection if needed |
| stdvga_crtc_write(crtc_addr, 0x11, GET_FARVAR(seg, info->crtc_regs[0x11])); |
| |
| // Set Attribute Ctl |
| for (i=0; i<20; i++) |
| stdvga_attr_write(i, GET_FARVAR(seg, info->actl_regs[i])); |
| stdvga_attrindex_write(GET_FARVAR(seg, info->actl_index)); |
| |
| for (i=0; i<9; i++) |
| stdvga_grdc_write(i, GET_FARVAR(seg, info->grdc_regs[i])); |
| |
| outb(GET_FARVAR(seg, info->sequ_index), VGAREG_SEQU_ADDRESS); |
| outb(GET_FARVAR(seg, info->crtc_index), crtc_addr); |
| outb(GET_FARVAR(seg, info->grdc_index), VGAREG_GRDC_ADDRESS); |
| outb(GET_FARVAR(seg, info->feature), crtc_addr - 0x4 + 0xa); |
| } |
| |
| struct saveDACcolors { |
| u8 rwmode; |
| u8 peladdr; |
| u8 pelmask; |
| u8 dac[768]; |
| u8 color_select; |
| } PACKED; |
| |
| static void |
| stdvga_save_dac_state(u16 seg, struct saveDACcolors *info) |
| { |
| /* XXX: check this */ |
| SET_FARVAR(seg, info->rwmode, inb(VGAREG_DAC_STATE)); |
| SET_FARVAR(seg, info->peladdr, inb(VGAREG_DAC_WRITE_ADDRESS)); |
| SET_FARVAR(seg, info->pelmask, stdvga_pelmask_read()); |
| stdvga_dac_read(seg, info->dac, 0, 256); |
| SET_FARVAR(seg, info->color_select, 0); |
| } |
| |
| static void |
| stdvga_restore_dac_state(u16 seg, struct saveDACcolors *info) |
| { |
| stdvga_pelmask_write(GET_FARVAR(seg, info->pelmask)); |
| stdvga_dac_write(seg, info->dac, 0, 256); |
| outb(GET_FARVAR(seg, info->peladdr), VGAREG_DAC_WRITE_ADDRESS); |
| } |
| |
| int |
| stdvga_save_restore(int cmd, u16 seg, void *data) |
| { |
| void *pos = data; |
| if (cmd & SR_HARDWARE) { |
| if (cmd & SR_SAVE) |
| stdvga_save_hw_state(seg, pos); |
| if (cmd & SR_RESTORE) |
| stdvga_restore_hw_state(seg, pos); |
| pos += sizeof(struct saveVideoHardware); |
| } |
| pos += bda_save_restore(cmd, seg, pos); |
| if (cmd & SR_DAC) { |
| if (cmd & SR_SAVE) |
| stdvga_save_dac_state(seg, pos); |
| if (cmd & SR_RESTORE) |
| stdvga_restore_dac_state(seg, pos); |
| pos += sizeof(struct saveDACcolors); |
| } |
| return pos - data; |
| } |
| |
| |
| /**************************************************************** |
| * Misc |
| ****************************************************************/ |
| |
| // Enable/disable system access to the video memory |
| void |
| stdvga_enable_video_addressing(u8 disable) |
| { |
| u8 v = (disable & 1) ? 0x00 : 0x02; |
| stdvga_misc_mask(0x02, v); |
| } |
| |
| int |
| stdvga_setup(void) |
| { |
| // switch to color mode and enable CPU access 480 lines |
| stdvga_misc_write(0xc3); |
| // more than 64k 3C4/04 |
| stdvga_sequ_write(0x04, 0x02); |
| |
| return 0; |
| } |