On 05/10/2021 10:50, Laurent Vivier wrote:
Le 04/10/2021 à 23:19, Mark Cave-Ayland a écrit :
The monitor modes table is found by experimenting with the Monitors Control
Panel in MacOS and analysing the reads/writes. From this it can be found that
the mode is controlled by writes to the DAFB_MODE_CTRL1 and DAFB_MODE_CTRL2
registers.
Implement the first block of DAFB registers as a register array including the
existing sense register, the newly discovered control registers above, and also
the DAFB_MODE_VADDR1 and DAFB_MODE_VADDR2 registers which are used by NetBSD to
determine the current video mode.
These experiments also show that the offset of the start of video RAM and the
stride can change depending upon the monitor mode, so update
macfb_draw_graphic()
and both the BI_MAC_VADDR and BI_MAC_VROW bootinfo for the q800 machine
accordingly.
Finally update macfb_common_realize() so that only the resolution and depth
supported by the display type can be specified on the command line.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
hw/display/macfb.c | 124 ++++++++++++++++++++++++++++++++-----
hw/display/trace-events | 1 +
hw/m68k/q800.c | 11 ++--
include/hw/display/macfb.h | 16 ++++-
4 files changed, 131 insertions(+), 21 deletions(-)
diff --git a/hw/display/macfb.c b/hw/display/macfb.c
index f98bcdec2d..357fe18be5 100644
--- a/hw/display/macfb.c
+++ b/hw/display/macfb.c
...
+static MacFbMode *macfb_find_mode(MacfbDisplayType display_type,
+ uint16_t width, uint16_t height,
+ uint8_t depth)
+{
+ MacFbMode *macfb_mode;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(macfb_mode_table); i++) {
+ macfb_mode = &macfb_mode_table[i];
+
+ if (display_type == macfb_mode->type && width == macfb_mode->width &&
+ height == macfb_mode->height && depth == macfb_mode->depth) {
+ return macfb_mode;
+ }
+ }
+
+ return NULL;
+}
+
I misunderstood this part when I reviewed v1...
It means you have to provide the monitor type to QEMU to switch from the
default mode?
Not as such: both the MacOS toolbox ROM and MacOS itself offer a fixed set of
resolutions and depths
based upon the display type. What I've done for now is default the display type
to VGA since it
offers both 640x480 and 800x600 in 1, 2, 4, 8, 16 and 24-bit colour which
should cover the most
common use of cases of people wanting to boot using the MacOS toolbox ROM.
Even if you specify a default on the command line, MacOS still only cares about
the display type and
will allow you to change the resolution and depth dynamically, remembering the
last resolution and
depth across reboots.
During testing I found that having access to the 1152x870 resolution offered by the
Apple 21"
monitor display type was useful to allow larger screen sizes, although only up
to 8-bit depth so I
added a bit of code that will switch from a VGA display type to a 21" display
type if the graphics
resolution is set to 1152x870x8.
Finally if you boot a Linux kernel directly using -kernel then the provided
XxYxD is placed directly
into the relevant bootinfo fields with a VGA display type, unless a resolution
of 1152x870x8 is
specified in which case the 21" display type is used as above.
But, as a user, how do we know which modes are allowed with which resolution?
Is possible to try to set internally the type here according to the resolution?
Could you provide an command line example how to start the q800 with the
1152x870 resolution?
Sure - simply add "-g 1152x870x8" to your command line. If the -g parameter is
omitted then the
display type will default to VGA.