historical/m0-applesillicon.git/xnu-qemu-arm64-5.1.0/roms/seabios/vgasrc/bochsdisplay.c
2024-01-16 11:20:27 -06:00

79 lines
2.6 KiB
C

// Simple framebuffer vgabios for use with qemu bochs-display device
//
// Copyright (C) 2019 Gerd Hoffmann <kraxel@redhat.com>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "biosvar.h" // GET_BDA
#include "output.h" // dprintf
#include "string.h" // memset16_far
#include "bochsvga.h" // VBE_BOCHS_*
#include "hw/pci.h" // pci_config_readl
#include "hw/pci_regs.h" // PCI_BASE_ADDRESS_0
#include "vgabios.h" // SET_VGA
#include "vgautil.h" // VBE_total_memory
#define FRAMEBUFFER_WIDTH 1024
#define FRAMEBUFFER_HEIGHT 768
#define FRAMEBUFFER_BPP 4
int
bochs_display_setup(void)
{
dprintf(1, "bochs-display: setup called\n");
if (GET_GLOBAL(HaveRunInit))
return 0;
int bdf = GET_GLOBAL(VgaBDF);
if (bdf == 0)
return 0;
u32 bar = pci_config_readl(bdf, PCI_BASE_ADDRESS_0);
u32 lfb_addr = bar & PCI_BASE_ADDRESS_MEM_MASK;
bar = pci_config_readl(bdf, PCI_BASE_ADDRESS_2);
u32 io_addr = bar & PCI_BASE_ADDRESS_IO_MASK;
dprintf(1, "bochs-display: bdf %02x:%02x.%x, bar 0 at 0x%x, bar 1 at 0x%x\n"
, pci_bdf_to_bus(bdf) , pci_bdf_to_dev(bdf), pci_bdf_to_fn(bdf),
lfb_addr, io_addr);
u16 *dispi = (void*)(io_addr + 0x500);
u8 *vga = (void*)(io_addr + 0x400);
u16 id = readw(dispi + VBE_DISPI_INDEX_ID);
dprintf(1, "bochs-display: id is 0x%x, %s\n", id
, id == VBE_DISPI_ID5 ? "good" : "FAIL");
if (id != VBE_DISPI_ID5)
return -1;
int i;
u8 *edid = (void*)(io_addr);
for (i = 0; i < sizeof(VBE_edid); i++)
SET_VGA(VBE_edid[i], readb(edid + i));
int fb_width = FRAMEBUFFER_WIDTH;
int fb_height = FRAMEBUFFER_HEIGHT;
if (GET_GLOBAL(VBE_edid[0]) == 0x00 &&
GET_GLOBAL(VBE_edid[1]) == 0xff) {
fb_width = GET_GLOBAL(VBE_edid[54 + 2]);
fb_width |= (GET_GLOBAL(VBE_edid[54 + 4]) & 0xf0) << 4;
fb_height = GET_GLOBAL(VBE_edid[54 + 5]);
fb_height |= (GET_GLOBAL(VBE_edid[54 + 7]) & 0xf0) << 4;
}
int fb_stride = FRAMEBUFFER_BPP * fb_width;
dprintf(1, "bochs-display: using %dx%d, %d bpp (%d stride)\n"
, fb_width, fb_height
, FRAMEBUFFER_BPP * 8, fb_stride);
cbvga_setup_modes(lfb_addr, FRAMEBUFFER_BPP * 8,
fb_width, fb_height, fb_stride);
writew(dispi + VBE_DISPI_INDEX_XRES, fb_width);
writew(dispi + VBE_DISPI_INDEX_YRES, fb_height);
writew(dispi + VBE_DISPI_INDEX_BPP, FRAMEBUFFER_BPP * 8);
writew(dispi + VBE_DISPI_INDEX_ENABLE, VBE_DISPI_ENABLED);
writeb(vga, 0x20); /* unblank (for qemu -device VGA) */
return 0;
}