vgabios: Make VBE code independent of bochsvga.

Introduce new global variables (VBE_enabled, VBE_total_memory,
VBE_capabilities, VBE_framebuffer) to replace the need for function
calls that were specific to bochsvga.

Replace info received from bochsvga_mode_info with info found in
vgahw_find_mode.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

4 files changed, 89 insertions, 144 deletions

diff --git a/vgasrc/bochsvga.c b/vgasrc/bochsvga.c
index 5ab1bc2..d9858c2 100644
--- a/vgasrc/bochsvga.c
+++ b/vgasrc/bochsvga.c
@@ -76,10 +76,6 @@ static struct bochsvga_mode
     { 0x18c, { MM_DIRECT, 2560, 1600, 32 } },
 };
 
-#define BYTES_PER_PIXEL(m) ((GET_GLOBAL((m)->depth) + 7) / 8)
-
-u32 pci_lfb_addr VAR16;
-
 static inline u32 pci_config_readl(u16 bdf, u16 addr)
 {
     int status;
@@ -101,7 +97,6 @@ static inline u32 pci_config_readl(u16 bdf, u16 addr)
     return val;
 }
 
-
 static u16 dispi_get_max_xres(void)
 {
     u16 en;
@@ -145,7 +140,7 @@ bochsvga_init(void)
         return -1;
     }
 
-    SET_BDA(vbe_flag, 0x1);
+    SET_VGA(VBE_enabled, 1);
     dispi_write(VBE_DISPI_INDEX_ID, VBE_DISPI_ID5);
 
     u32 lfb_addr;
@@ -154,51 +149,42 @@ bochsvga_init(void)
     else
         lfb_addr = VBE_DISPI_LFB_PHYSICAL_ADDRESS;
 
-    SET_FARVAR(get_global_seg(), pci_lfb_addr, lfb_addr);
+    SET_VGA(VBE_framebuffer, lfb_addr);
+    u16 totalmem = dispi_read(VBE_DISPI_INDEX_VIDEO_MEMORY_64K);
+    SET_VGA(VBE_total_memory, totalmem * 64 * 1024);
+    SET_VGA(VBE_capabilities, VBE_CAPABILITY_8BIT_DAC);
 
-    dprintf(1, "VBE DISPI detected. lfb_addr=%x\n", GET_GLOBAL(pci_lfb_addr));
+    dprintf(1, "VBE DISPI detected. lfb_addr=%x\n", lfb_addr);
 
     return 0;
 }
 
-int
-bochsvga_enabled(void)
+static int mode_valid(struct vgamode_s *vmode_g)
 {
-    return GET_BDA(vbe_flag);
-}
+    u16 max_xres = dispi_get_max_xres();
+    u16 max_bpp = dispi_get_max_bpp();
+    u32 max_mem = GET_GLOBAL(VBE_total_memory);
 
-u16
-bochsvga_total_mem(void)
-{
-    return dispi_read(VBE_DISPI_INDEX_VIDEO_MEMORY_64K);
+    u16 width = GET_GLOBAL(vmode_g->width);
+    u16 height = GET_GLOBAL(vmode_g->height);
+    u8 depth = GET_GLOBAL(vmode_g->depth);
+    u32 mem = width * height * DIV_ROUND_UP(depth, 8);
+
+    return width <= max_xres && depth <= max_bpp && mem <= max_mem;
 }
 
 struct vgamode_s *bochsvga_find_mode(int mode)
 {
     struct bochsvga_mode *m = bochsvga_modes;
     for (; m < &bochsvga_modes[ARRAY_SIZE(bochsvga_modes)]; m++)
-        if (GET_GLOBAL(m->mode) == mode)
+        if (GET_GLOBAL(m->mode) == mode) {
+            if (! mode_valid(&m->info))
+                return NULL;
             return &m->info;
+        }
     return stdvga_find_mode(mode);
 }
 
-static int mode_valid(struct vgamode_s *vmode_g)
-{
-    u16 max_xres = dispi_get_max_xres();
-    u16 max_bpp = dispi_get_max_bpp();
-    u32 max_mem = bochsvga_total_mem() * 64 * 1024;
-
-    u32 mem = GET_GLOBAL(vmode_g->width) * GET_GLOBAL(vmode_g->height) *
-              BYTES_PER_PIXEL(vmode_g);
-
-    if (GET_GLOBAL(vmode_g->width) > max_xres ||
-        GET_GLOBAL(vmode_g->depth) > max_bpp ||
-        mem > max_mem)
-        return 0;
-
-    return 1;
-}
-
 void
 bochsvga_list_modes(u16 seg, u16 *dest, u16 *last)
 {
@@ -215,25 +201,7 @@ bochsvga_list_modes(u16 seg, u16 *dest, u16 *last)
     stdvga_list_modes(seg, dest, last);
 }
 
-int
-bochsvga_mode_info(u16 mode, struct vbe_modeinfo *info)
-{
-    struct vgamode_s *vmode_g = bochsvga_find_mode(mode);
-    if (!vmode_g || !mode_valid(vmode_g))
-        return -1;
-
-    info->width = GET_GLOBAL(vmode_g->width);
-    info->height = GET_GLOBAL(vmode_g->height);
-    info->depth = GET_GLOBAL(vmode_g->depth);
-
-    info->linesize = info->width * ((info->depth + 7) / 8);
-    info->phys_base = GET_GLOBAL(pci_lfb_addr);
-    info->vram_size = bochsvga_total_mem() * 64 * 1024;
-
-    return 0;
-}
-
-void
+static void
 bochsvga_hires_enable(int enable)
 {
     u16 flags = enable ?
@@ -244,43 +212,56 @@ bochsvga_hires_enable(int enable)
     dispi_write(VBE_DISPI_INDEX_ENABLE, flags);
 }
 
+static void
+bochsvga_clear_scr(void)
+{
+    u16 en;
+
+    en = dispi_read(VBE_DISPI_INDEX_ENABLE);
+    en &= ~VBE_DISPI_NOCLEARMEM;
+    dispi_write(VBE_DISPI_INDEX_ENABLE, en);
+}
+
 int
 bochsvga_set_mode(int mode, int flags)
 {
     if (!(mode & VBE_MODE_VESA_DEFINED)) {
         dprintf(1, "set VGA mode %x\n", mode);
 
+        SET_BDA(vbe_mode, 0);
         bochsvga_hires_enable(0);
         return stdvga_set_mode(mode, flags);
     }
 
-    struct vbe_modeinfo modeinfo, *info = &modeinfo;
-    int ret = bochsvga_mode_info(mode, &modeinfo);
-    if (ret) {
+    struct vgamode_s *vmode_g = bochsvga_find_mode(mode);
+    if (!vmode_g) {
         dprintf(1, "VBE mode %x not found\n", mode);
         return VBE_RETURN_STATUS_FAILED;
     }
     bochsvga_hires_enable(1);
 
-    if (info->depth == 4)
+    u8 depth = GET_GLOBAL(vmode_g->depth);
+    if (depth == 4)
         stdvga_set_mode(0x6a, 0);
-    if (info->depth == 8)
+    if (depth == 8)
         // XXX load_dac_palette(3);
         ;
 
-    dispi_write(VBE_DISPI_INDEX_BPP, info->depth);
-    dispi_write(VBE_DISPI_INDEX_XRES, info->width);
-    dispi_write(VBE_DISPI_INDEX_YRES, info->height);
+    dispi_write(VBE_DISPI_INDEX_BPP, depth);
+    u16 width = GET_GLOBAL(vmode_g->width);
+    u16 height = GET_GLOBAL(vmode_g->height);
+    dispi_write(VBE_DISPI_INDEX_XRES, width);
+    dispi_write(VBE_DISPI_INDEX_YRES, height);
     dispi_write(VBE_DISPI_INDEX_BANK, 0);
 
     /* VGA compat setup */
     //XXX: This probably needs some reverse engineering
     u8 v;
     outw(0x0011, VGAREG_VGA_CRTC_ADDRESS);
-    outw(((info->width * 4 - 1) << 8) | 0x1, VGAREG_VGA_CRTC_ADDRESS);
-    dispi_write(VBE_DISPI_INDEX_VIRT_WIDTH, info->width);
-    outw(((info->height - 1) << 8) | 0x12, VGAREG_VGA_CRTC_ADDRESS);
-    outw(((info->height - 1) & 0xff00) | 0x7, VGAREG_VGA_CRTC_ADDRESS);
+    outw(((width * 4 - 1) << 8) | 0x1, VGAREG_VGA_CRTC_ADDRESS);
+    dispi_write(VBE_DISPI_INDEX_VIRT_WIDTH, width);
+    outw(((height - 1) << 8) | 0x12, VGAREG_VGA_CRTC_ADDRESS);
+    outw(((height - 1) & 0xff00) | 0x7, VGAREG_VGA_CRTC_ADDRESS);
     v = inb(VGAREG_VGA_CRTC_DATA) & 0xbd;
     if (v & 0x1)
         v |= 0x2;
@@ -298,7 +279,7 @@ bochsvga_set_mode(int mode, int flags)
     outb(0x20, VGAREG_ACTL_ADDRESS);
     outw(0x0506, VGAREG_GRDC_ADDRESS);
     outw(0x0f02, VGAREG_SEQU_ADDRESS);
-    if (info->depth >= 8) {
+    if (depth >= 8) {
         outb(0x14, VGAREG_VGA_CRTC_ADDRESS);
         outb(inb(VGAREG_VGA_CRTC_DATA) | 0x40, VGAREG_VGA_CRTC_DATA);
         v = inb(VGAREG_ACTL_RESET);
@@ -314,7 +295,7 @@ bochsvga_set_mode(int mode, int flags)
         outb(v | 0x40, VGAREG_GRDC_DATA);
     }
 
-    SET_BDA(vbe_mode, mode);
+    SET_BDA(vbe_mode, mode | flags);
 
     if (flags & MF_LINEARFB) {
         /* Linear frame buffer */
@@ -326,25 +307,3 @@ bochsvga_set_mode(int mode, int flags)
 
     return 0;
 }
-
-void
-bochsvga_clear_scr(void)
-{
-    u16 en;
-
-    en = dispi_read(VBE_DISPI_INDEX_ENABLE);
-    en &= ~VBE_DISPI_NOCLEARMEM;
-    dispi_write(VBE_DISPI_INDEX_ENABLE, en);
-}
-
-int
-bochsvga_hires_enabled(void)
-{
-    return dispi_read(VBE_DISPI_INDEX_ENABLE) & VBE_DISPI_ENABLED;
-}
-
-u16
-bochsvga_curr_mode(void)
-{
-    return GET_BDA(vbe_mode);
-}
diff --git a/vgasrc/bochsvga.h b/vgasrc/bochsvga.h
index c08f103..a9cedbf 100644
--- a/vgasrc/bochsvga.h
+++ b/vgasrc/bochsvga.h
@@ -53,16 +53,8 @@ static inline void dispi_write(u16 reg, u16 val)
 }
 
 int bochsvga_init(void);
-int bochsvga_enabled(void);
-u16 bochsvga_total_mem(void);
 void bochsvga_list_modes(u16 seg, u16 *dest, u16 *last);
-struct vbe_modeinfo;
-int bochsvga_mode_info(u16 mode, struct vbe_modeinfo *info);
-void bochsvga_hires_enable(int enable);
 struct vgamode_s *bochsvga_find_mode(int mode);
 int bochsvga_set_mode(int mode, int flags);
-void bochsvga_clear_scr(void);
-int bochsvga_hires_enabled(void);
-u16 bochsvga_curr_mode(void);
 
 #endif // bochsvga.h
diff --git a/vgasrc/vbe.c b/vgasrc/vbe.c
index daf8c51..d764a0c 100644
--- a/vgasrc/vbe.c
+++ b/vgasrc/vbe.c
@@ -11,9 +11,13 @@
 #include "vbe.h" // struct vbe_info
 #include "util.h" // dprintf
 #include "biosvar.h" // get_global_set
-#include "bochsvga.h" // bochsvga_hires_enabled
 #include "vgahw.h" // vgahw_set_mode
 
+int VBE_enabled VAR16;
+u32 VBE_total_memory VAR16 = 256 * 1024;
+u32 VBE_capabilities VAR16;
+u32 VBE_framebuffer VAR16;
+
 static void
 vbe_104f00(struct bregs *regs)
 {
@@ -36,14 +40,15 @@ vbe_104f00(struct bregs *regs)
 
     SET_FARVAR(seg, info->oem_string,
             SEGOFF(get_global_seg(), (u32)VBE_OEM_STRING));
-    SET_FARVAR(seg, info->capabilities, 0x1); /* 8BIT DAC */
+    SET_FARVAR(seg, info->capabilities, GET_GLOBAL(VBE_capabilities));
 
     /* We generate our mode list in the reserved field of the info block */
     u16 *destmode = (void*)info->reserved;
     SET_FARVAR(seg, info->video_mode, SEGOFF(seg, (u32)destmode));
 
     /* Total memory (in 64 blocks) */
-    SET_FARVAR(seg, info->total_memory, bochsvga_total_mem());
+    SET_FARVAR(seg, info->total_memory
+               , GET_GLOBAL(VBE_total_memory) / (64*1024));
 
     SET_FARVAR(seg, info->oem_vendor_string,
             SEGOFF(get_global_seg(), (u32)VBE_VENDOR_STRING));
@@ -56,8 +61,7 @@ vbe_104f00(struct bregs *regs)
     u16 *last = (void*)&info->reserved[sizeof(info->reserved)];
     vgahw_list_modes(seg, destmode, last - 1);
 
-    regs->al = regs->ah; /* 0x4F, Function supported */
-    regs->ah = 0x0; /* 0x0, Function call successful */
+    regs->ax = 0x004f;
 }
 
 static void
@@ -66,15 +70,13 @@ vbe_104f01(struct bregs *regs)
     u16 seg = regs->es;
     struct vbe_mode_info *info = (void*)(regs->di+0);
     u16 mode = regs->cx;
-    struct vbe_modeinfo modeinfo;
-    int rc;
 
     dprintf(1, "VBE mode info request: %x\n", mode);
 
-    rc = bochsvga_mode_info(mode, &modeinfo);
-    if (rc) {
+    struct vgamode_s *vmode_g = vgahw_find_mode(mode);
+    if (! vmode_g) {
         dprintf(1, "VBE mode %x not found\n", mode);
-        regs->ax = 0x100;
+        regs->ax = 0x0100;
         return;
     }
 
@@ -82,7 +84,8 @@ vbe_104f01(struct bregs *regs)
                     VBE_MODE_ATTRIBUTE_EXTENDED_INFORMATION_AVAILABLE |
                     VBE_MODE_ATTRIBUTE_COLOR_MODE |
                     VBE_MODE_ATTRIBUTE_GRAPHICS_MODE;
-    if (modeinfo.depth == 4)
+    int depth = GET_GLOBAL(vmode_g->depth);
+    if (depth == 4)
         mode_attr |= VBE_MODE_ATTRIBUTE_TTY_BIOS_SUPPORT;
     else
         mode_attr |= VBE_MODE_ATTRIBUTE_LINEAR_FRAME_BUFFER_MODE;
@@ -97,27 +100,29 @@ vbe_104f01(struct bregs *regs)
     SET_FARVAR(seg, info->winA_seg, 0xA000);
     SET_FARVAR(seg, info->winB_seg, 0x0);
     SET_FARVAR(seg, info->win_func_ptr.segoff, 0x0);
-    SET_FARVAR(seg, info->bytes_per_scanline, modeinfo.linesize);
-    SET_FARVAR(seg, info->xres, modeinfo.width);
-    SET_FARVAR(seg, info->yres, modeinfo.height);
+    int width = GET_GLOBAL(vmode_g->width);
+    int height = GET_GLOBAL(vmode_g->height);
+    int linesize = width * DIV_ROUND_UP(depth, 8); // XXX - not always true
+    SET_FARVAR(seg, info->bytes_per_scanline, linesize);
+    SET_FARVAR(seg, info->xres, width);
+    SET_FARVAR(seg, info->yres, height);
     SET_FARVAR(seg, info->xcharsize, 8);
     SET_FARVAR(seg, info->ycharsize, 16);
-    if (modeinfo.depth == 4)
+    if (depth == 4)
         SET_FARVAR(seg, info->planes, 4);
     else
         SET_FARVAR(seg, info->planes, 1);
-    SET_FARVAR(seg, info->bits_per_pixel, modeinfo.depth);
-    SET_FARVAR(seg, info->banks,
-            (modeinfo.linesize * modeinfo.height + 65535) / 65536);
-    if (modeinfo.depth == 4)
+    SET_FARVAR(seg, info->bits_per_pixel, depth);
+    SET_FARVAR(seg, info->banks, DIV_ROUND_UP(linesize * height, 64*1024));
+    if (depth == 4)
         SET_FARVAR(seg, info->mem_model, VBE_MEMORYMODEL_PLANAR);
-    else if (modeinfo.depth == 8)
+    else if (depth == 8)
         SET_FARVAR(seg, info->mem_model, VBE_MEMORYMODEL_PACKED_PIXEL);
     else
         SET_FARVAR(seg, info->mem_model, VBE_MEMORYMODEL_DIRECT_COLOR);
     SET_FARVAR(seg, info->bank_size, 0);
-    u32 pages = modeinfo.vram_size / (modeinfo.height * modeinfo.linesize);
-    if (modeinfo.depth == 4)
+    u32 pages = GET_GLOBAL(VBE_total_memory) / (height * linesize);
+    if (depth == 4)
         SET_FARVAR(seg, info->pages, (pages / 4) - 1);
     else
         SET_FARVAR(seg, info->pages, pages - 1);
@@ -125,7 +130,7 @@ vbe_104f01(struct bregs *regs)
 
     u8 r_size, r_pos, g_size, g_pos, b_size, b_pos, a_size, a_pos;
 
-    switch (modeinfo.depth) {
+    switch (depth) {
     case 15: r_size = 5; r_pos = 10; g_size = 5; g_pos = 5;
              b_size = 5; b_pos = 0; a_size = 1; a_pos = 15; break;
     case 16: r_size = 5; r_pos = 11; g_size = 6; g_pos = 5;
@@ -147,20 +152,20 @@ vbe_104f01(struct bregs *regs)
     SET_FARVAR(seg, info->alpha_size, a_size);
     SET_FARVAR(seg, info->alpha_pos, a_pos);
 
-    if (modeinfo.depth == 32)
+    if (depth == 32)
         SET_FARVAR(seg, info->directcolor_info,
                    VBE_DIRECTCOLOR_RESERVED_BITS_AVAILABLE);
     else
         SET_FARVAR(seg, info->directcolor_info, 0);
 
-    if (modeinfo.depth > 4)
-        SET_FARVAR(seg, info->phys_base, modeinfo.phys_base);
+    if (depth > 4)
+        SET_FARVAR(seg, info->phys_base, GET_GLOBAL(VBE_framebuffer));
     else
         SET_FARVAR(seg, info->phys_base, 0);
 
     SET_FARVAR(seg, info->reserved1, 0);
     SET_FARVAR(seg, info->reserved2, 0);
-    SET_FARVAR(seg, info->linear_bytes_per_scanline, modeinfo.linesize);
+    SET_FARVAR(seg, info->linear_bytes_per_scanline, linesize);
     SET_FARVAR(seg, info->bank_pages, 0);
     SET_FARVAR(seg, info->linear_pages, 0);
     SET_FARVAR(seg, info->linear_red_size, r_size);
@@ -173,8 +178,7 @@ vbe_104f01(struct bregs *regs)
     SET_FARVAR(seg, info->linear_alpha_pos, a_pos);
     SET_FARVAR(seg, info->pixclock_max, 0);
 
-    regs->al = regs->ah; /* 0x4F, Function supported */
-    regs->ah = 0x0; /* 0x0, Function call successful */
+    regs->ax = 0x004f;
 }
 
 static void
@@ -193,16 +197,13 @@ vbe_104f02(struct bregs *regs)
 static void
 vbe_104f03(struct bregs *regs)
 {
-    if (!bochsvga_hires_enabled()) {
+    u16 mode = GET_BDA(vbe_mode);
+    if (!mode)
         regs->bx = GET_BDA(video_mode);
-    } else {
-        regs->bx = bochsvga_curr_mode();
-    }
 
     dprintf(1, "VBE current mode=%x\n", regs->bx);
 
-    regs->al = regs->ah; /* 0x4F, Function supported */
-    regs->ah = 0x0; /* 0x0, Function call successful */
+    regs->ax = 0x004f;
 }
 
 static void
@@ -257,7 +258,7 @@ vbe_104fXX(struct bregs *regs)
 void
 handle_104f(struct bregs *regs)
 {
-    if (!bochsvga_enabled()) {
+    if (!GET_GLOBAL(VBE_enabled)) {
         vbe_104fXX(regs);
         return;
     }
diff --git a/vgasrc/vgabios.h b/vgasrc/vgabios.h
index 3416b98..464100b 100644
--- a/vgasrc/vgabios.h
+++ b/vgasrc/vgabios.h
@@ -83,21 +83,14 @@ void vgafb_write_pixel(u8 color, u16 x, u16 y);
 u8 vgafb_read_pixel(u16 x, u16 y);
 
 // vbe.c
+int VBE_enabled;
+u32 VBE_total_memory;
+u32 VBE_capabilities;
+u32 VBE_framebuffer;
 #define VBE_OEM_STRING "SeaBIOS VBE(C) 2011"
 #define VBE_VENDOR_STRING "SeaBIOS Developers"
 #define VBE_PRODUCT_STRING "SeaBIOS VBE Adapter"
 #define VBE_REVISION_STRING "Rev. 1"
-
-struct vbe_modeinfo
-{
-    u16 width;
-    u16 height;
-    u8 depth;
-    u16 linesize;
-    u32 phys_base;
-    u32 vram_size;
-};
-
 struct bregs;
 void handle_104f(struct bregs *regs);