Commit graph

3 commits

Author SHA1 Message Date
Bin Meng
ffe1c8379e video: bochs: Avoid using IO instructions to access VGA IO port
At present the driver uses IO instructions to access the legacy
VGA IO ports, which unfortunately limits the driver to work only
on x86. It turns out the IO instruction is not necessary as Bochs
VGA card remaps the legacy VGA IO ports (0x3c0 -> 0x3df) to its
memory mapped register space from offset 0x400.

Update the driver to use MMIO access for VGA IO port.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>  # qemu-x86_64
2023-08-01 13:31:29 +02:00
Bin Meng
caae795a1c video: bochs: Drop the useless argument of bochs_vga_write()
bochs_vga_write() takes 'index' as one argument, but never uses it.

While we are here, use macros instead of magic numbers for the
VGA IO port register name and value.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>  # qemu-x86_64
2023-08-01 13:30:41 +02:00
Simon Glass
e2d934b4da x86: video: Add a driver for QEMU bochs emulation
Bochs is convenient with QEMU on x86 since it does not require a video
BIOS. Add a driver for it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2023-07-17 17:23:15 +08:00