x86/boot/video-vesa.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /* -*- linux-c -*- ------------------------------------------------------- *
0003  *
0004  *   Copyright (C) 1991, 1992 Linus Torvalds
0005  *   Copyright 2007 rPath, Inc. - All Rights Reserved
0006  *   Copyright 2009 Intel Corporation; author H. Peter Anvin
0007  *
0008  * ----------------------------------------------------------------------- */
0009
0010 /*
0011  * VESA text modes
0012  */
0013
0014 #include "boot.h"
0015 #include "video.h"
0016 #include "vesa.h"
0017 #include "string.h"
0018
0019 /* VESA information */
0020 static struct vesa_general_info vginfo;
0021 static struct vesa_mode_info vminfo;
0022
0023 static __videocard video_vesa;
0024
0025 #ifndef _WAKEUP
0026 static void vesa_store_mode_params_graphics(void);
0027 #else /* _WAKEUP */
0028 static inline void vesa_store_mode_params_graphics(void) {}
0029 #endif /* _WAKEUP */
0030
0031 static int vesa_probe(void)
0032 {
0033     struct biosregs ireg, oreg;
0034     u16 mode;
0035     addr_t mode_ptr;
0036     struct mode_info *mi;
0037     int nmodes = 0;
0038
0039     video_vesa.modes = GET_HEAP(struct mode_info, 0);
0040
0041     initregs(&ireg);
0042     ireg.ax = 0x4f00;
0043     ireg.di = (size_t)&vginfo;
0044     intcall(0x10, &ireg, &oreg);
0045
0046     if (oreg.ax != 0x004f ||
0047         vginfo.signature != VESA_MAGIC ||
0048         vginfo.version < 0x0102)
0049         return 0;   /* Not present */
0050
0051     set_fs(vginfo.video_mode_ptr.seg);
0052     mode_ptr = vginfo.video_mode_ptr.off;
0053
0054     while ((mode = rdfs16(mode_ptr)) != 0xffff) {
0055         mode_ptr += 2;
0056
0057         if (!heap_free(sizeof(struct mode_info)))
0058             break;  /* Heap full, can't save mode info */
0059
0060         if (mode & ~0x1ff)
0061             continue;
0062
0063         memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */
0064
0065         ireg.ax = 0x4f01;
0066         ireg.cx = mode;
0067         ireg.di = (size_t)&vminfo;
0068         intcall(0x10, &ireg, &oreg);
0069
0070         if (oreg.ax != 0x004f)
0071             continue;
0072
0073         if ((vminfo.mode_attr & 0x15) == 0x05) {
0074             /* Text Mode, TTY BIOS supported,
0075                supported by hardware */
0076             mi = GET_HEAP(struct mode_info, 1);
0077             mi->mode  = mode + VIDEO_FIRST_VESA;
0078             mi->depth = 0; /* text */
0079             mi->x     = vminfo.h_res;
0080             mi->y     = vminfo.v_res;
0081             nmodes++;
0082         } else if ((vminfo.mode_attr & 0x99) == 0x99 &&
0083                (vminfo.memory_layout == 4 ||
0084                 vminfo.memory_layout == 6) &&
0085                vminfo.memory_planes == 1) {
0086 #ifdef CONFIG_BOOT_VESA_SUPPORT
0087             /* Graphics mode, color, linear frame buffer
0088                supported.  Only register the mode if
0089                if framebuffer is configured, however,
0090                otherwise the user will be left without a screen. */
0091             mi = GET_HEAP(struct mode_info, 1);
0092             mi->mode = mode + VIDEO_FIRST_VESA;
0093             mi->depth = vminfo.bpp;
0094             mi->x = vminfo.h_res;
0095             mi->y = vminfo.v_res;
0096             nmodes++;
0097 #endif
0098         }
0099     }
0100
0101     return nmodes;
0102 }
0103
0104 static int vesa_set_mode(struct mode_info *mode)
0105 {
0106     struct biosregs ireg, oreg;
0107     int is_graphic;
0108     u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
0109
0110     memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */
0111
0112     initregs(&ireg);
0113     ireg.ax = 0x4f01;
0114     ireg.cx = vesa_mode;
0115     ireg.di = (size_t)&vminfo;
0116     intcall(0x10, &ireg, &oreg);
0117
0118     if (oreg.ax != 0x004f)
0119         return -1;
0120
0121     if ((vminfo.mode_attr & 0x15) == 0x05) {
0122         /* It's a supported text mode */
0123         is_graphic = 0;
0124 #ifdef CONFIG_BOOT_VESA_SUPPORT
0125     } else if ((vminfo.mode_attr & 0x99) == 0x99) {
0126         /* It's a graphics mode with linear frame buffer */
0127         is_graphic = 1;
0128         vesa_mode |= 0x4000; /* Request linear frame buffer */
0129 #endif
0130     } else {
0131         return -1;  /* Invalid mode */
0132     }
0133
0134
0135     initregs(&ireg);
0136     ireg.ax = 0x4f02;
0137     ireg.bx = vesa_mode;
0138     intcall(0x10, &ireg, &oreg);
0139
0140     if (oreg.ax != 0x004f)
0141         return -1;
0142
0143     graphic_mode = is_graphic;
0144     if (!is_graphic) {
0145         /* Text mode */
0146         force_x = mode->x;
0147         force_y = mode->y;
0148         do_restore = 1;
0149     } else {
0150         /* Graphics mode */
0151         vesa_store_mode_params_graphics();
0152     }
0153
0154     return 0;
0155 }
0156
0157
0158 #ifndef _WAKEUP
0159
0160 /* Switch DAC to 8-bit mode */
0161 static void vesa_dac_set_8bits(void)
0162 {
0163     struct biosregs ireg, oreg;
0164     u8 dac_size = 6;
0165
0166     /* If possible, switch the DAC to 8-bit mode */
0167     if (vginfo.capabilities & 1) {
0168         initregs(&ireg);
0169         ireg.ax = 0x4f08;
0170         ireg.bh = 0x08;
0171         intcall(0x10, &ireg, &oreg);
0172         if (oreg.ax == 0x004f)
0173             dac_size = oreg.bh;
0174     }
0175
0176     /* Set the color sizes to the DAC size, and offsets to 0 */
0177     boot_params.screen_info.red_size   = dac_size;
0178     boot_params.screen_info.green_size = dac_size;
0179     boot_params.screen_info.blue_size  = dac_size;
0180     boot_params.screen_info.rsvd_size  = dac_size;
0181
0182     boot_params.screen_info.red_pos    = 0;
0183     boot_params.screen_info.green_pos  = 0;
0184     boot_params.screen_info.blue_pos   = 0;
0185     boot_params.screen_info.rsvd_pos   = 0;
0186 }
0187
0188 /* Save the VESA protected mode info */
0189 static void vesa_store_pm_info(void)
0190 {
0191     struct biosregs ireg, oreg;
0192
0193     initregs(&ireg);
0194     ireg.ax = 0x4f0a;
0195     intcall(0x10, &ireg, &oreg);
0196
0197     if (oreg.ax != 0x004f)
0198         return;
0199
0200     boot_params.screen_info.vesapm_seg = oreg.es;
0201     boot_params.screen_info.vesapm_off = oreg.di;
0202 }
0203
0204 /*
0205  * Save video mode parameters for graphics mode
0206  */
0207 static void vesa_store_mode_params_graphics(void)
0208 {
0209     /* Tell the kernel we're in VESA graphics mode */
0210     boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
0211
0212     /* Mode parameters */
0213     boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
0214     boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
0215     boot_params.screen_info.lfb_width = vminfo.h_res;
0216     boot_params.screen_info.lfb_height = vminfo.v_res;
0217     boot_params.screen_info.lfb_depth = vminfo.bpp;
0218     boot_params.screen_info.pages = vminfo.image_planes;
0219     boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
0220     memcpy(&boot_params.screen_info.red_size,
0221            &vminfo.rmask, 8);
0222
0223     /* General parameters */
0224     boot_params.screen_info.lfb_size = vginfo.total_memory;
0225
0226     if (vminfo.bpp <= 8)
0227         vesa_dac_set_8bits();
0228
0229     vesa_store_pm_info();
0230 }
0231
0232 /*
0233  * Save EDID information for the kernel; this is invoked, separately,
0234  * after mode-setting.
0235  */
0236 void vesa_store_edid(void)
0237 {
0238 #ifdef CONFIG_FIRMWARE_EDID
0239     struct biosregs ireg, oreg;
0240
0241     /* Apparently used as a nonsense token... */
0242     memset(&boot_params.edid_info, 0x13, sizeof(boot_params.edid_info));
0243
0244     if (vginfo.version < 0x0200)
0245         return;     /* EDID requires VBE 2.0+ */
0246
0247     initregs(&ireg);
0248     ireg.ax = 0x4f15;       /* VBE DDC */
0249     /* ireg.bx = 0x0000; */     /* Report DDC capabilities */
0250     /* ireg.cx = 0; */      /* Controller 0 */
0251     ireg.es = 0;            /* ES:DI must be 0 by spec */
0252     intcall(0x10, &ireg, &oreg);
0253
0254     if (oreg.ax != 0x004f)
0255         return;     /* No EDID */
0256
0257     /* BH = time in seconds to transfer EDD information */
0258     /* BL = DDC level supported */
0259
0260     ireg.ax = 0x4f15;       /* VBE DDC */
0261     ireg.bx = 0x0001;       /* Read EDID */
0262     /* ireg.cx = 0; */      /* Controller 0 */
0263     /* ireg.dx = 0; */      /* EDID block number */
0264     ireg.es = ds();
0265     ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
0266     intcall(0x10, &ireg, &oreg);
0267 #endif /* CONFIG_FIRMWARE_EDID */
0268 }
0269
0270 #endif /* not _WAKEUP */
0271
0272 static __videocard video_vesa =
0273 {
0274     .card_name  = "VESA",
0275     .probe      = vesa_probe,
0276     .set_mode   = vesa_set_mode,
0277     .xmode_first    = VIDEO_FIRST_VESA,
0278     .xmode_n    = 0x200,
0279 };