pci: Add general support for execution of video ROMs

Some platforms don't have native code for dealing with their video
hardware. In some cases they use a binary blob to set it up and perform
required actions like setting the video mode. This approach is a hangover
from the old PC days where a ROM was provided and executed during startup.

Even now, these ROMs are supplied as a way to set up video. It avoids the
code for every video chip needing to be provided in the boot loader. But
it makes the video much less flexible - e.g. it is not possible to do
anything else while the video init is happening (including waiting hundreds
of milliseconds for display panels to start up).

In any case, to deal with this sad state of affairs, provide an API for
execution of x86 video ROMs, either natively or through emulation.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/include/pci_rom.h b/include/pci_rom.h
new file mode 100644
index 0000000..8b2674c
--- /dev/null
+++ b/include/pci_rom.h
@@ -0,0 +1,58 @@
+/*
+ * From coreboot file of same name
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _PCI_ROM_H
+#define _PCI_ROM_H
+
+#define PCI_ROM_HDR			0xaa55
+#define PCI_VGA_RAM_IMAGE_START		0xc0000
+
+struct pci_rom_header {
+	uint16_t signature;
+	uint8_t size;
+	uint8_t init[3];
+	uint8_t reserved[0x12];
+	uint16_t data;
+};
+
+struct pci_rom_data {
+	uint32_t signature;
+	uint16_t vendor;
+	uint16_t device;
+	uint16_t reserved_1;
+	uint16_t dlen;
+	uint8_t drevision;
+	uint8_t class_lo;
+	uint16_t class_hi;
+	uint16_t ilen;
+	uint16_t irevision;
+	uint8_t type;
+	uint8_t indicator;
+	uint16_t reserved_2;
+};
+
+ /**
+ * pci_run_vga_bios() - Run the VGA BIOS in an x86 PC
+ *
+ * @dev:	Video device containing the BIOS
+ * @int15_handler:	Function to call to handle int 0x15
+ * @emulate:	true to use the x86 emulator, false to run native
+ */
+int pci_run_vga_bios(pci_dev_t dev, int (*int15_handler)(void), bool emulate);
+
+/**
+ * board_map_oprom_vendev() - map several PCI IDs to the one the ROM expects
+ *
+ * Some VGA option roms are used for several chipsets but they only have one
+ * PCI ID in their header. If we encounter such an option rom, we need to do
+ * the mapping ourselves.
+ *
+ * @vendev:	Vendor and device for the video device
+ * @return standard vendor and device expected by the ROM
+ */
+uint32_t board_map_oprom_vendev(uint32_t vendev);
+
+#endif