diff options
| -rw-r--r-- | arch/x86/machine/cga.c | 111 |
1 files changed, 58 insertions, 53 deletions
diff --git a/arch/x86/machine/cga.c b/arch/x86/machine/cga.c index 8e03b502..e364b917 100644 --- a/arch/x86/machine/cga.c +++ b/arch/x86/machine/cga.c @@ -46,17 +46,22 @@ /* * I/O ports. */ -#define CGA_MISC_OUTPUT_REGISTER_READ 0x3cc -#define CGA_MISC_OUTPUT_REGISTER_WRITE 0x3c2 -#define CGA_CRTC_ADDRESS_REGISTER 0x3d4 -#define CGA_CRTC_DATA_REGISTER 0x3d5 +#define CGA_PORT_MISC_OUT_READ 0x3cc +#define CGA_PORT_MISC_OUT_WRITE 0x3c2 +#define CGA_PORT_CRTC_ADDR 0x3d4 +#define CGA_PORT_CRTC_DATA 0x3d5 + +/* + * Miscellaneous output register bits. + */ +#define CGA_MISC_OUT_IOAS 0x1 /* * CRTC registers. */ -#define CGA_CRTC_CURSOR_START_REGISTER 0xa -#define CGA_CRTC_CURSOR_LOCATION_HIGH_REGISTER 0xe -#define CGA_CRTC_CURSOR_LOCATION_LOW_REGISTER 0xf +#define CGA_CRTC_CURSOR_START_REG 0xa +#define CGA_CRTC_CURSOR_LOC_HIGH_REG 0xe +#define CGA_CRTC_CURSOR_LOC_LOW_REG 0xf /* * Cursor start register bits. @@ -110,12 +115,12 @@ cga_get_cursor_position(void) { uint16_t tmp; - io_write_byte(CGA_CRTC_ADDRESS_REGISTER, - CGA_CRTC_CURSOR_LOCATION_HIGH_REGISTER); - tmp = io_read_byte(CGA_CRTC_DATA_REGISTER) << 8; - io_write_byte(CGA_CRTC_ADDRESS_REGISTER, - CGA_CRTC_CURSOR_LOCATION_LOW_REGISTER); - tmp |= io_read_byte(CGA_CRTC_DATA_REGISTER); + io_write_byte(CGA_PORT_CRTC_ADDR, + CGA_CRTC_CURSOR_LOC_HIGH_REG); + tmp = io_read_byte(CGA_PORT_CRTC_DATA) << 8; + io_write_byte(CGA_PORT_CRTC_ADDR, + CGA_CRTC_CURSOR_LOC_LOW_REG); + tmp |= io_read_byte(CGA_PORT_CRTC_DATA); return tmp; } @@ -123,12 +128,10 @@ cga_get_cursor_position(void) static void cga_set_cursor_position(uint16_t position) { - io_write_byte(CGA_CRTC_ADDRESS_REGISTER, - CGA_CRTC_CURSOR_LOCATION_HIGH_REGISTER); - io_write_byte(CGA_CRTC_DATA_REGISTER, position >> 8); - io_write_byte(CGA_CRTC_ADDRESS_REGISTER, - CGA_CRTC_CURSOR_LOCATION_LOW_REGISTER); - io_write_byte(CGA_CRTC_DATA_REGISTER, position & 0xff); + io_write_byte(CGA_PORT_CRTC_ADDR, CGA_CRTC_CURSOR_LOC_HIGH_REG); + io_write_byte(CGA_PORT_CRTC_DATA, position >> 8); + io_write_byte(CGA_PORT_CRTC_ADDR, CGA_CRTC_CURSOR_LOC_LOW_REG); + io_write_byte(CGA_PORT_CRTC_DATA, position & 0xff); } static void @@ -136,9 +139,9 @@ cga_enable_cursor(void) { uint8_t tmp; - io_write_byte(CGA_CRTC_ADDRESS_REGISTER, CGA_CRTC_CURSOR_START_REGISTER); - tmp = io_read_byte(CGA_CRTC_DATA_REGISTER); - io_write_byte(CGA_CRTC_DATA_REGISTER, tmp & ~CGA_CSR_DISABLED); + io_write_byte(CGA_PORT_CRTC_ADDR, CGA_CRTC_CURSOR_START_REG); + tmp = io_read_byte(CGA_PORT_CRTC_DATA); + io_write_byte(CGA_PORT_CRTC_DATA, tmp & ~CGA_CSR_DISABLED); } static void @@ -146,9 +149,9 @@ cga_disable_cursor(void) { uint8_t tmp; - io_write_byte(CGA_CRTC_ADDRESS_REGISTER, CGA_CRTC_CURSOR_START_REGISTER); - tmp = io_read_byte(CGA_CRTC_DATA_REGISTER); - io_write_byte(CGA_CRTC_DATA_REGISTER, tmp | CGA_CSR_DISABLED); + io_write_byte(CGA_PORT_CRTC_ADDR, CGA_CRTC_CURSOR_START_REG); + tmp = io_read_byte(CGA_PORT_CRTC_DATA); + io_write_byte(CGA_PORT_CRTC_DATA, tmp | CGA_CSR_DISABLED); } static void @@ -397,51 +400,53 @@ cga_bbuf_scroll_down(struct cga_bbuf *bbuf) void cga_putc(char c) { - if (c == '\r') { + unsigned int i; + + switch (c) { + case '\r': return; - } else if (c == '\n') { + case '\n': cga_bbuf_newline(&cga_bbuf); - } else if (c == '\b') { + break; + case '\b': cga_bbuf_backspace(&cga_bbuf); - } else if (c == '\t') { - int i; - + break; + case '\t': for(i = 0; i < CGA_TABULATION_SPACES; i++) { cga_putc(' '); } - } else if (c == CONSOLE_SCROLL_UP) { + + break; + case CONSOLE_SCROLL_UP: cga_bbuf_scroll_up(&cga_bbuf); - } else if (c == CONSOLE_SCROLL_DOWN) { + break; + case CONSOLE_SCROLL_DOWN: cga_bbuf_scroll_down(&cga_bbuf); - } else { + break; + default: cga_bbuf_push(&cga_bbuf, c); } } -void __init -cga_setup(void) +static void __init +cga_setup_misc_out(void) { - uint8_t misc_output_register; + uint8_t reg; - cga_memory = (void *)vm_page_direct_va(CGA_MEMORY); + reg = io_read_byte(CGA_PORT_MISC_OUT_READ); - /* - * Check if the Input/Output Address Select bit is set. - */ - misc_output_register = io_read_byte(CGA_MISC_OUTPUT_REGISTER_READ); - - if (!(misc_output_register & 0x1)) { - /* - * Set the I/O AS bit. - */ - misc_output_register |= 0x1; - - /* - * Update the misc output register. - */ - io_write_byte(CGA_MISC_OUTPUT_REGISTER_WRITE, misc_output_register); + if (!(reg & CGA_MISC_OUT_IOAS)) { + reg |= CGA_MISC_OUT_IOAS; + io_write_byte(CGA_PORT_MISC_OUT_WRITE, reg); } +} + +void __init +cga_setup(void) +{ + cga_memory = (void *)vm_page_direct_va(CGA_MEMORY); + cga_setup_misc_out(); cga_bbuf_init(&cga_bbuf, cga_get_cursor_position()); } |