/** Set the display mode.
* @param _dev Device to set mode of.
* @param mode Mode structure for mode to set.
* @return Status code describing result of the operation. */
static status_t vbe_display_set_mode(display_device_t *_device, display_mode_t *mode) {
bios_regs_t regs;
if(mode) {
/* Check if anything needs to be done. */
bios_regs_init(®s);
regs.eax = VBE_FUNCTION_GET_MODE;
bios_interrupt(0x10, ®s);
if((regs.eax & 0xFF00) != 0) {
kprintf(LOG_DEBUG, "vbe: call failed with code 0x%x\n", regs.eax & 0xFFFF);
return STATUS_DEVICE_ERROR;
}
if((regs.ebx & ~((1<<14) | (1<<15))) == mode->id) {
return STATUS_SUCCESS;
}
kprintf(LOG_DEBUG, "vbe: switching to mode 0x%" PRIx32 " (mode: %p)\n", mode->id, mode);
}
/* Set bit 14 in the mode register to use linear framebuffer model. */
bios_regs_init(®s);
regs.eax = VBE_FUNCTION_SET_MODE;
regs.ebx = (mode) ? (mode->id | (1<<14)) : 3;
bios_interrupt(0x10, ®s);
if((regs.eax & 0xFF00) != 0) {
kprintf(LOG_DEBUG, "vbe: call failed with code 0x%x\n", regs.eax & 0xFFFF);
return STATUS_DEVICE_ERROR;
}
return STATUS_SUCCESS;
}
/**
* Get the PXE entry point address.
*
* @return Whether the entry point could be found.
*/
static bool get_entry_point(void) {
bios_regs_t regs;
pxenv_t *pxenv;
pxe_t *pxe;
/* Use the PXE installation check function. */
bios_regs_init(®s);
regs.eax = INT1A_PXE_INSTALL_CHECK;
bios_call(0x1a, ®s);
if (regs.eax != INT1A_PXE_INSTALL_CHECK_RET || regs.eflags & X86_FLAGS_CF) {
dprintf("pxe: loaded via PXE but PXE not available\n");
return false;
}
/* Get the PXENV+ structure. */
pxenv = (pxenv_t *)segoff_to_linear((regs.es << 16) | regs.bx);
if (memcmp(pxenv->signature, PXENV_SIGNATURE, sizeof(pxenv->signature)) != 0) {
boot_error("PXENV+ structure has incorrect signature");
} else if (!checksum_range(pxenv, pxenv->length)) {
boot_error("PXENV+ structure is corrupt");
}
/* Get the !PXE structure. */
pxe = (pxe_t *)segoff_to_linear(pxenv->pxe_ptr);
if (memcmp(pxe->signature, PXE_SIGNATURE, sizeof(pxe->signature)) != 0) {
boot_error("!PXE structure has incorrect signature");
} else if (!checksum_range(pxe, pxe->length)) {
boot_error("!PXE structure is corrupt");
}
pxe_entry_point = pxe->entry_point_16;
return true;
}
/** Initialisation function for the VBE driver.
* @return Status code describing result of the operation. */
static status_t vbe_init(void) {
phys_ptr_t mem_phys = ~((phys_ptr_t)0);
size_t count = 0, i, mem_size = 0;
vbe_mode_info_t *minfo = NULL;
display_mode_t *modes = NULL;
vbe_info_t *info = NULL;
uint16_t *location;
bios_regs_t regs;
status_t ret;
/* Detect VBE presence by trying to get controller information. */
info = bios_mem_alloc(sizeof(vbe_info_t), MM_WAIT);
strncpy(info->vbe_signature, "VBE2", 4);
bios_regs_init(®s);
regs.eax = VBE_FUNCTION_CONTROLLER_INFO;
regs.edi = bios_mem_virt2phys(info);
bios_interrupt(0x10, ®s);
if((regs.eax & 0x00FF) != 0x4F) {
kprintf(LOG_DEBUG, "vbe: VBE is not supported!\n");
ret = STATUS_NOT_SUPPORTED;
goto out;
} else if((regs.eax & 0xFF00) != 0) {
kprintf(LOG_DEBUG, "vbe: call failed with code 0x%x\n", regs.eax & 0xFFFF);
ret = STATUS_DEVICE_ERROR;
goto out;
}
kprintf(LOG_NOTICE, "vbe: vbe presence was detected:\n");
kprintf(LOG_NOTICE, " signature: %s\n", info->vbe_signature);
kprintf(LOG_NOTICE, " version: 0x%" PRIx16 "\n", info->vbe_version);
kprintf(LOG_NOTICE, " capabilities: 0x%" PRIx32 "\n", info->capabilities);
kprintf(LOG_NOTICE, " mode pointer: 0x%" PRIx32 "\n", info->video_mode_ptr);
kprintf(LOG_NOTICE, " total memory: %" PRIu16 "KB\n", info->total_memory * 64);
if(info->vbe_version >= 0x0200) {
kprintf(LOG_NOTICE, " OEM revision: 0x%" PRIx16 "\n", info->oem_software_rev);
}
mem_size = (info->total_memory * 64) * 1024;
location = bios_mem_phys2virt(SEGOFF2LIN(info->video_mode_ptr));
if(!location) {
ret = STATUS_DEVICE_ERROR;
goto out;
}
/* Allocate a region to store the mode information structure in. */
minfo = bios_mem_alloc(sizeof(vbe_mode_info_t), MM_WAIT);
/* Iterate through all the modes available. An ID of 0xFFFF indicates
* the end of the mode list. */
for(i = 0; location[i] != 0xFFFF; i++) {
/* Get information on the mode. */
bios_regs_init(®s);
regs.eax = VBE_FUNCTION_MODE_INFO;
regs.ecx = location[i];
regs.edi = bios_mem_virt2phys(minfo);
bios_interrupt(0x10, ®s);
if((regs.eax & 0xFF00) != 0) {
kprintf(LOG_DEBUG, "vbe: call failed with code 0x%x\n", regs.eax & 0xFFFF);
ret = STATUS_DEVICE_ERROR;
goto out;
}
/* Check if the mode is suitable. */
if(minfo->memory_model != 4 && minfo->memory_model != 6) {
/* Not packed-pixel or direct colour. */
continue;
} else if(minfo->phys_base_ptr == 0) {
/* Borked. */
continue;
} else if((minfo->mode_attributes & (1<<0)) == 0) {
/* Not supported. */
continue;
} else if((minfo->mode_attributes & (1<<3)) == 0) {
/* Not colour. */
continue;
} else if((minfo->mode_attributes & (1<<4)) == 0) {
/* Not a graphics mode. */
continue;
} else if((minfo->mode_attributes & (1<<7)) == 0) {
/* Not usable in linear mode. */
continue;
} else if(minfo->bits_per_pixel != 8 && minfo->bits_per_pixel != 16 &&
minfo->bits_per_pixel != 24 && minfo->bits_per_pixel != 32) {
continue;
}
/* Add the mode to the mode array. To begin with, set offset to
* the full physical address. */
modes = krealloc(modes, sizeof(display_mode_t) * (count + 1), MM_WAIT);
modes[count].id = location[i];
modes[count].width = minfo->x_resolution;
modes[count].height = minfo->y_resolution;
modes[count].format = depth_to_format(minfo->bits_per_pixel);
modes[count].offset = minfo->phys_base_ptr;
count++;
/* Try to guess the memory address. */
if(minfo->phys_base_ptr < mem_phys) {
mem_phys = minfo->phys_base_ptr;
}
}
/* Now fix up mode offsets. */
for(i = 0; i < count; i++) {
modes[i].offset = modes[i].offset - mem_phys;
}
/* Set the cache mode on the framebuffer to WC. */
phys_set_memory_type(mem_phys, ROUND_UP(mem_size, PAGE_SIZE), MEMORY_TYPE_WC);
/* Add the display device. */
ret = display_device_create(NULL, NULL, &vbe_display_ops, NULL, modes, count,
mem_phys, mem_size, &vbe_display_device);
if(ret != STATUS_SUCCESS) {
return ret;
}
out:
if(minfo) {
bios_mem_free(minfo, sizeof(vbe_mode_info_t));
}
if(info) {
bios_mem_free(info, sizeof(vbe_info_t));
}
return ret;
}