| Message ID | 20211002110007.30825-4-mark.cave-ayland@ilande.co.uk |
|---|---|
| State | New |
| Headers | show |
| Series | macfb: fixes for booting MacOS | expand |
Le 02/10/2021 à 12:59, Mark Cave-Ayland a écrit : > The palette_current index counter has a maximum size of 256 * 3 to cover a full > color palette of 256 RGB entries. Linux assumes that the palette_current index > wraps back around to zero after writing 256 RGB entries so ensure that > palette_current is reset at this point to prevent data corruption within > MacfbState. > > Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> > --- > hw/display/macfb.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/hw/display/macfb.c b/hw/display/macfb.c > index 815870f2fe..f4e789d0d7 100644 > --- a/hw/display/macfb.c > +++ b/hw/display/macfb.c > @@ -307,6 +307,9 @@ static void macfb_ctrl_write(void *opaque, > if (s->palette_current % 3) { > macfb_invalidate_display(s); > } > + if (s->palette_current >= sizeof(s->color_palette)) { > + s->palette_current = 0; > + } > break; > } > } > What about "s->palette_current = (s->palette_current + 1) % sizeof(s->color_palette)"? Thanks, Laurent
On 04/10/2021 09:53, Laurent Vivier wrote: > Le 02/10/2021 à 12:59, Mark Cave-Ayland a écrit : >> The palette_current index counter has a maximum size of 256 * 3 to cover a full >> color palette of 256 RGB entries. Linux assumes that the palette_current index >> wraps back around to zero after writing 256 RGB entries so ensure that >> palette_current is reset at this point to prevent data corruption within >> MacfbState. >> >> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> >> --- >> hw/display/macfb.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/hw/display/macfb.c b/hw/display/macfb.c >> index 815870f2fe..f4e789d0d7 100644 >> --- a/hw/display/macfb.c >> +++ b/hw/display/macfb.c >> @@ -307,6 +307,9 @@ static void macfb_ctrl_write(void *opaque, >> if (s->palette_current % 3) { >> macfb_invalidate_display(s); >> } >> + if (s->palette_current >= sizeof(s->color_palette)) { >> + s->palette_current = 0; >> + } >> break; >> } >> } >> > > What about "s->palette_current = (s->palette_current + 1) % sizeof(s->color_palette)"? > > Thanks, > Laurent Sure, I can update that for v2. ATB, Mark.
diff --git a/hw/display/macfb.c b/hw/display/macfb.c index 815870f2fe..f4e789d0d7 100644 --- a/hw/display/macfb.c +++ b/hw/display/macfb.c @@ -307,6 +307,9 @@ static void macfb_ctrl_write(void *opaque, if (s->palette_current % 3) { macfb_invalidate_display(s); } + if (s->palette_current >= sizeof(s->color_palette)) { + s->palette_current = 0; + } break; } }
The palette_current index counter has a maximum size of 256 * 3 to cover a full color palette of 256 RGB entries. Linux assumes that the palette_current index wraps back around to zero after writing 256 RGB entries so ensure that palette_current is reset at this point to prevent data corruption within MacfbState. Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> --- hw/display/macfb.c | 3 +++ 1 file changed, 3 insertions(+)