blob: 7efb11fbebcdaf9950a51f457793da1b21558558 [file] [log] [blame]
// Simple framebuffer vgabios for use with qemu ramfb 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 "vgautil.h" // VBE_total_memory
#include "std/pmm.h" // struct pmmheader
#include "byteorder.h"
#include "fw/paravirt.h"
/* ---------------------------------------------------------------------- */
/* minimal qemu fc_cfg support bits, requires dma support */
#define QEMU_CFG_FILE_DIR 0x19
struct QemuCfgFile {
u32 size; /* file size */
u16 select; /* write this to 0x510 to read it */
u16 reserved;
char name[56];
};
static void
qemu_cfg_dma_transfer(void *address, u32 length, u32 control)
{
QemuCfgDmaAccess access;
if (length == 0) {
return;
}
access.address = cpu_to_be64((u64)(u32)address);
access.length = cpu_to_be32(length);
access.control = cpu_to_be32(control);
barrier();
outl(cpu_to_be32((u32)&access), PORT_QEMU_CFG_DMA_ADDR_LOW);
while(be32_to_cpu(access.control) & ~QEMU_CFG_DMA_CTL_ERROR)
/* wait */;
}
static void
qemu_cfg_read(void *buf, int len)
{
qemu_cfg_dma_transfer(buf, len, QEMU_CFG_DMA_CTL_READ);
}
static void
qemu_cfg_read_entry(void *buf, int e, int len)
{
u32 control = (e << 16) | QEMU_CFG_DMA_CTL_SELECT
| QEMU_CFG_DMA_CTL_READ;
qemu_cfg_dma_transfer(buf, len, control);
}
static void
qemu_cfg_write_entry(void *buf, int e, int len)
{
u32 control = (e << 16) | QEMU_CFG_DMA_CTL_SELECT
| QEMU_CFG_DMA_CTL_WRITE;
qemu_cfg_dma_transfer(buf, len, control);
}
static int
qemu_cfg_find_file(const char *filename)
{
u32 count, e, select;
qemu_cfg_read_entry(&count, QEMU_CFG_FILE_DIR, sizeof(count));
count = be32_to_cpu(count);
for (select = 0, e = 0; e < count; e++) {
struct QemuCfgFile qfile;
qemu_cfg_read(&qfile, sizeof(qfile));
if (memcmp_far(GET_SEG(SS), qfile.name,
GET_SEG(CS), filename, 10) == 0)
select = be16_to_cpu(qfile.select);
}
return select;
}
/* ---------------------------------------------------------------------- */
#define FRAMEBUFFER_WIDTH 1024
#define FRAMEBUFFER_HEIGHT 768
#define FRAMEBUFFER_BPP 4
#define FRAMEBUFFER_STRIDE (FRAMEBUFFER_BPP * FRAMEBUFFER_WIDTH)
#define FRAMEBUFFER_SIZE (FRAMEBUFFER_STRIDE * FRAMEBUFFER_HEIGHT)
struct QemuRAMFBCfg {
u64 addr;
u32 fourcc;
u32 flags;
u32 width;
u32 height;
u32 stride;
};
#define fourcc_code(a, b, c, d) ((u32)(a) | ((u32)(b) << 8) | \
((u32)(c) << 16) | ((u32)(d) << 24))
#define DRM_FORMAT_RGB565 fourcc_code('R', 'G', '1', '6') /* [15:0] R:G:B 5:6:5 little endian */
#define DRM_FORMAT_RGB888 fourcc_code('R', 'G', '2', '4') /* [23:0] R:G:B little endian */
#define DRM_FORMAT_XRGB8888 fourcc_code('X', 'R', '2', '4') /* [31:0] x:R:G:B 8:8:8:8 little endian */
static u32
allocate_framebuffer(void)
{
u32 res = allocate_pmm(FRAMEBUFFER_SIZE, 1, 1);
if (!res)
return 0;
dprintf(1, "ramfb: framebuffer allocated at %x\n", res);
return res;
}
int
ramfb_setup(void)
{
dprintf(1, "ramfb: init\n");
if (GET_GLOBAL(HaveRunInit))
return 0;
u32 select = qemu_cfg_find_file("etc/ramfb");
if (select == 0) {
dprintf(1, "ramfb: fw_cfg (etc/ramfb) file not found\n");
return -1;
}
dprintf(1, "ramfb: fw_cfg (etc/ramfb) file at slot 0x%x\n", select);
u32 fb = allocate_framebuffer();
if (!fb) {
dprintf(1, "ramfb: allocating framebuffer failed\n");
return -1;
}
u64 addr = fb;
u8 bpp = FRAMEBUFFER_BPP * 8;
u32 xlines = FRAMEBUFFER_WIDTH;
u32 ylines = FRAMEBUFFER_HEIGHT;
u32 linelength = FRAMEBUFFER_STRIDE;
dprintf(1, "Found FB @ %llx %dx%d with %d bpp (%d stride)\n"
, addr, xlines, ylines, bpp, linelength);
if (!addr || addr > 0xffffffff
|| (bpp != 15 && bpp != 16 && bpp != 24 && bpp != 32)) {
dprintf(1, "Unable to use FB\n");
return -1;
}
cbvga_setup_modes(addr, bpp, xlines, ylines, linelength);
struct QemuRAMFBCfg cfg = {
.addr = cpu_to_be64(fb),
.fourcc = cpu_to_be32(DRM_FORMAT_XRGB8888),
.flags = cpu_to_be32(0),
.width = cpu_to_be32(FRAMEBUFFER_WIDTH),
.height = cpu_to_be32(FRAMEBUFFER_HEIGHT),
.stride = cpu_to_be32(FRAMEBUFFER_STRIDE),
};
qemu_cfg_write_entry(&cfg, select, sizeof(cfg));
return 0;
}