From f6acdfb863038a45709f0dc57884742c51fa6f07 Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Mon, 9 Mar 2015 20:21:20 +0100 Subject: Implement V86 monitor and VESA mode detection. --- src/kernel/dev/vesa.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 src/kernel/dev/vesa.c (limited to 'src/kernel/dev/vesa.c') diff --git a/src/kernel/dev/vesa.c b/src/kernel/dev/vesa.c new file mode 100644 index 0000000..6b23a34 --- /dev/null +++ b/src/kernel/dev/vesa.c @@ -0,0 +1,84 @@ +#include + +#include +#include + +// ---- VESA data structures + +typedef struct { + char vbe_signature[4]; // == "VESA" + uint16_t vbe_version; + v86_farptr_t oem_string_ptr; + uint8_t capabilities[4]; + v86_farptr_t video_mode_ptr; + uint16_t total_memory; // as # of 64KB blocks +} __attribute__((packed)) vbe_info_block_t; + +typedef struct { + uint16_t attributes; + uint8_t winA, winB; + uint16_t granularity; + uint16_t winsize; + uint16_t segmentA, segmentB; + v86_farptr_t real_fct_ptr; + uint16_t pitch; // bytes per scanline + + uint16_t Xres, Yres; + uint8_t Wchar, Ychar, planes, bpp, banks; + uint8_t memory_model, bank_size, image_pages; + uint8_t reserved0; + + uint8_t red_mask, red_position; + uint8_t green_mask, green_position; + uint8_t blue_mask, blue_position; + uint8_t rsv_mask, rsv_position; + uint8_t directcolor_attributes; + + uint32_t physbase; // the offset of the framebuffer in physical memory! + uint32_t reserved1; + uint16_t reserved2; +} __attribute__((packed)) vbe_mode_info_block_t; + +// ---- VESA code + +void vesa_detect(fs_t *iofs) { + if (!v86_begin_session()) return; + + vbe_info_block_t *i = (vbe_info_block_t*)v86_alloc(512); + memset(i, 0, 512); + strncpy(i->vbe_signature, "VBE2", 4); + + v86_regs.ax = 0x4F00; + v86_regs.es = V86_SEG_OF_LIN(i); + v86_regs.di = V86_OFF_OF_LIN(i); + + if (v86_bios_int(0x10)) { + if (v86_regs.ax == 0x004F) { + dbg_printf("Detected VESA (sig %s, ver 0x%x, oem %s) with %d kb ram.\n", + i->vbe_signature, i->vbe_version, v86_lin_of_fp(i->oem_string_ptr), 64 * i->total_memory); + + vbe_mode_info_block_t *mi = (vbe_mode_info_block_t*)v86_alloc(256); + + uint16_t *modes = (uint16_t*)v86_lin_of_fp(i->video_mode_ptr); + for (int n = 0; modes[n] != 0xFFFF; n++) { + v86_regs.ax = 0x4F01; + v86_regs.cx = modes[n]; + v86_regs.es = V86_SEG_OF_LIN(mi); + v86_regs.di = V86_OFF_OF_LIN(mi); + if (v86_bios_int(0x10) && v86_regs.ax == 0x004F) { + dbg_printf("Mode 0x%x : %dx%dx%d at 0x%p\n", modes[n], mi->Xres, mi->Yres, mi->bpp, mi->physbase); + } else { + dbg_printf("Mode 0x%x : could not get info\n", modes[n]); + } + } + } else { + dbg_printf("Error in BIOS int 0x10/0x4F00.\n"); + } + } else { + dbg_printf("Could not call BIOS int 0x10.\n"); + } + + v86_end_session(); +} + +/* vim: set ts=4 sw=4 tw=0 noet :*/ -- cgit v1.2.3