diff options
Diffstat (limited to 'int10vga.h')
| -rw-r--r-- | int10vga.h | 91 |
1 files changed, 85 insertions, 6 deletions
@@ -2,6 +2,7 @@ #define INT10_H #include <stdint.h> +#include <conio.h> #define BIOS_DATA_AREA_SEGMENT 0x40 @@ -191,23 +192,101 @@ static inline uint8_t __far * get_video_scanline(const struct modeinfo *info, un } } +enum vga_io_ports { + VGA_PORT_SC_ADDRESS = 0x3c4, + VGA_PORT_SC_DATA = 0x3c5, + VGA_PORT_GC_ADDRESS = 0x3ce, + VGA_PORT_GC_DATA = 0x3cf +}; + +enum vga_sc_regs { + VGA_SC_REG_MAP_MASK = 2 +}; + +enum vga_gc_regs { + VGA_GC_REG_SET_RESET = 0, + VGA_GC_REG_ENABLE_SET_RESET = 1, + VGA_GC_REG_DATA_ROTATE = 3, + VGA_GC_REG_READ_MAP = 4, + VGA_GC_REG_GRAPHICS_MODE = 5, + VGA_GC_REG_BIT_MASK = 8 +}; + struct videoregs { - uint16_t dummy; + uint8_t sc_reg; + uint8_t sc_map_mask; + uint8_t gc_reg; + uint8_t gc_enable_set_reset; + uint8_t gc_data_rotate; + uint8_t gc_graphics_mode; + uint8_t gc_read_map; + uint8_t gc_bit_mask; }; -static void save_video_registers(struct videoregs *regs) +static inline uint8_t vga_sc_reg_read(uint8_t reg) +{ + outp(VGA_PORT_SC_ADDRESS, reg); + return inp(VGA_PORT_SC_DATA); +} + +static inline void vga_sc_reg_write(uint8_t reg, uint8_t val) +{ + // Do one 16-bit write, the higher part will be the data while the lower byte the register. + outpw(VGA_PORT_SC_ADDRESS, (val << 8) | reg); +} + +static inline uint8_t vga_gc_reg_read(uint8_t reg) { - // TODO + outp(VGA_PORT_GC_ADDRESS, reg); + return inp(VGA_PORT_GC_DATA); } -static void restore_video_registers(struct videoregs *regs) +static inline void vga_gc_reg_write(uint8_t reg, uint8_t val) { - // TODO + outpw(VGA_PORT_GC_ADDRESS, (val << 8) | reg); +} + +static void vga_save_registers(struct videoregs __far *regs) +{ + regs->sc_reg = inp(VGA_PORT_SC_ADDRESS); + regs->sc_map_mask = vga_sc_reg_read(VGA_SC_REG_MAP_MASK); + regs->gc_reg = inp(VGA_PORT_GC_ADDRESS); + regs->gc_enable_set_reset = vga_gc_reg_read(VGA_GC_REG_ENABLE_SET_RESET); + regs->gc_data_rotate = vga_gc_reg_read(VGA_GC_REG_DATA_ROTATE); + regs->gc_read_map = vga_gc_reg_read(VGA_GC_REG_READ_MAP); + regs->gc_graphics_mode = vga_gc_reg_read(VGA_GC_REG_GRAPHICS_MODE); + regs->gc_bit_mask = vga_gc_reg_read(VGA_GC_REG_BIT_MASK); +} + +static void vga_restore_register(struct videoregs __far *regs) +{ + vga_sc_reg_write(VGA_SC_REG_MAP_MASK, regs->sc_map_mask); + outp(VGA_PORT_SC_ADDRESS, regs->sc_reg); + vga_gc_reg_write(VGA_GC_REG_ENABLE_SET_RESET, regs->gc_enable_set_reset); + vga_gc_reg_write(VGA_GC_REG_DATA_ROTATE, regs->gc_data_rotate); + vga_gc_reg_write(VGA_GC_REG_READ_MAP, regs->gc_read_map); + vga_gc_reg_write(VGA_GC_REG_GRAPHICS_MODE, regs->gc_graphics_mode); + vga_gc_reg_write(VGA_GC_REG_BIT_MASK, regs->gc_bit_mask); + outp(VGA_PORT_GC_ADDRESS, regs->gc_reg); +} + +static void vga_set_graphics_mode(struct videoregs __far *regs, unsigned read, unsigned write) +{ + vga_gc_reg_write(VGA_GC_REG_GRAPHICS_MODE, (regs->gc_graphics_mode & ~(8|3)) + | ((read << 3) & 8) | write & 3); + if (write == 0) { + // Set registers to a reasonable default ... + vga_gc_reg_write(VGA_GC_REG_ENABLE_SET_RESET, 0); + vga_gc_reg_write(VGA_GC_REG_DATA_ROTATE, 0); + vga_gc_reg_write(VGA_GC_REG_BIT_MASK, 0xFF); + } } static inline void vga_select_plane(unsigned plane) { - // TODO + vga_gc_reg_write(VGA_GC_REG_READ_MAP, plane & 0x3); + vga_sc_reg_write(VGA_SC_REG_MAP_MASK, 1 << plane); + } #endif |