The change makes the user and kernel address spaces on i386
independent, giving each almost the full 4G of usable virtual addresses
except for one PDE at top used for trampoline and per-CPU trampoline
stacks, and system structures that must be always mapped, namely IDT,
GDT, common TSS and LDT, and process-private TSS and LDT if allocated.
By using 1:1 mapping for the kernel text and data, it appeared
possible to eliminate assembler part of the locore.S which bootstraps
initial page table and KPTmap. The code is rewritten in C and moved
into the pmap_cold(). The comment in vmparam.h explains the KVA
layout.
There is no PCID mechanism available in protected mode, so each
kernel/user switch forth and back completely flushes the TLB, except
for the trampoline PTD region. The TLB invalidations for userspace
becomes trivial, because IPI handlers switch page tables. On the other
hand, context switches no longer need to reload %cr3.
copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for
new copyout(9) is compatibility with wiring user buffers around sysctl
handlers. This explains two kind of locks for copyout ptes and
accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow
path, is only tried after the 'fast path' failed, which temporary
changes mapping to the userspace and copies the data to/from small
per-cpu buffer in the trampoline. If a page fault occurs during the
copy, it is short-circuit by exception.s to not even reach C code.
The change was motivated by the need to implement the Meltdown
mitigation, but instead of KPTI the full split is done. The i386
architecture already shows the sizing problems, in particular, it is
impossible to link clang and lld with debugging. I expect that the
issues due to the virtual address space limits would only exaggerate
and the split gives more liveness to the platform.
Tested by: pho
Discussed with: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D14633
opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.
Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.
Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.
Reviewed by: kib, cem, jhb, jtl
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14941
Normally, shutdown_nice() just signals init. However, sometimes it
calls kern_reboot directly. For that case, r331298 dropped the Giant
lock before calling it. This turns out to be incorrect for the more
common case where init exists and we just signal it. Restore the old
behavior. The direct call to kern_reboot() doesn't sync buffers to the
disk, so should work with Giant held, so we don't need to drop locks
here for that.
Noticed by: bde@
Sponsored by: Netflix
Uses of mallocarray(9).
The use of mallocarray(9) has rocketed the required swap to build FreeBSD.
This is likely caused by the allocation size attributes which put extra pressure
on the compiler.
Given that most of these checks are superfluous we have to choose better
where to use mallocarray(9). We still have more uses of mallocarray(9) but
hopefully this is enough to bring swap usage to a reasonable level.
Reported by: wosch
PR: 225197
Focus on code where we are doing multiplications within malloc(9). None of
these is likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.
This initial sweep only covers malloc(9) calls with M_NOWAIT. No good
reason but I started doing the changes before r327796 and at that time it
was convenient to make sure the sorrounding code could handle NULL values.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
- Do not report T-axis wheel events as button presses
- Reverse T-axis to match Linux
- Remove wrong comment. T-axis buttons state should be checked by level not
by edge to allow continuous wheel tilt reporting
Reviewed by: gonzo
Approved by: gonzo (mentor)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D12676
- map the hard-coded frame buffer address above KERNBASE. Using the
physical address only worked because of larger mapping bugs.
The hard-coded frame buffer address only works on x86. Use messy ifdefs
to try to avoid warnings about unused code for other arches.
- remove the sysctl for reading and writing the table kernel console
attributes. Writing only worked for emergency output since normal
output uses unalterd copies.
- fix the test for the emergency console being usable
- explain why a hard-coded attribute is used very early. Emergency output
works on x86 even before the pcpu pointer is initialized.
Advertise this by changing the defaults to mostly red. If you don't like
this, change them (almost) back using:
vidcontrol -c charcolors,base=7,height=0
vidcontrol -c mousecolors,base=0[,height=15]
The (graphics mode only) mouse cursor colors were hard-coded to a black
border and lightwhite interior. Black for the border is the worst
possible default, since it is the same as the default black background
and not good for any dark background. Reversing this gives the better
default of X Windows. Coloring everything works better still. Now
the coloring defaults to a lightwhite border and red interior.
Coloring for the character cursor is more complicated and mode
dependent. The new coloring doesn't apply for hardware cursors. For
non-block cursors, it only applies in graphics mode. In text mode,
the cursor color was usually a hard-coded (dull)white for the background
only, unless the foreground was white when it was a hard-coded black
for the background only, unless the foreground was white and the
background was black it was reverse video. In graphics mode, it was
always reverse video for the block cursor. Reverse video is worse,
especially over cutmarking regions, since cutmarking still uses simple
reverse video (nothing better is possible in text mode) and double
reverse video for the cursor gives normal video. Now, graphics mode
uses the same algorithm as the best case for text mode in all cases
for graphics mode. The hard-coded sequence { white, black, } for the
background is now { red, white, blue, } where the first 2 colors can
be configured. The blue color at the end is a sentinel which prevents
reverse video being used in most cases but breaks the compatibility
setting for white on black and black on white characters. This will
be fixed later. The compatibility setting is most needed for mono modes.
The previous commit to syscons.c changed sc_cnterm() to be more careful.
It followed null pointers in some cases. But sc_cnterm() has been
unreachable for 15+ years since changes for multiple consoles turned
off calls to the the cnterm destructor for all console drivers. Before
them, it was only called at boot time. So no driver with an attached
console has ever been unloadable and not even the non-console destructors
have been tested much.
terminal state for kernel console output.
r56043 in 2000 added many complications to support dynamic selection
of the terminal emulator using modules and the ioctl CONS_SETTERM.
This was never completed. There are still no modules, but it is easy
to restore the scterm and dumb emulators at compile time. Then
boot-time configuration for the preferred one doesn't work right, but
CONS_SETTERM almost works after fixing this bug. CONS_SETTERM only
switches the emulator for the user state, leaving the kernel state(s)
still using the boot-time emulator. The fix is especially important
when switching from sc to scteken, since the scteken state has pointers
in it.
Rename kernel_console_ts to sc_kts.
There was already a per-vty defaults field, but it was useless since it was
only initialized when propagating the global settings and thus no different
from the current global settings and not per-vty. The global defaults field
was also invariant after boot time, but not quite so useless.
Fix this by adding a second selection bit the the control flags of the
relevant ioctl(). vidcontrol doesn't support this yet. Setting either
default propagates the change to the current setting for the same level
and then to all lower levels.
Improve the 3-way escape sequence used by termcap to control the cursor.
The "normal" (ve) case has always used reset, so the user could set
it to anything, but since the reset is to a global value this is not
very useful, especially since the "very visible" (vs) case doesn't
reset but inconsistently forces to a blinking block. Change vs to
first reset and then XOR the blinking bit so that it is predictably
different from ve.
attribute field is curs_attr. The base field holds user data translated
in a reversible way and is needed because current field holds this in
an irreversible way for efficiency.
Factor out some common code for the reversible translation. This is
slightly simpler now, and much easier to expand.
Translate the magic flags value -1 to a single control flag internally
up front so other flags can be trusted later. This can be used for the
relevant ioctl() too.
Remove CONS_CURSOR_FLAGS which contained all the control flags. It was
unused and not useful. After adding more flags, there will be tests on
a couple at a time but never on them all. This API should have used this
to disallow unknown flags.
redundant initializations.
Hard-code base = 0, height = (approx. 1/8 of the boot-time font height)
in all cases, and remove the BIOS/MD support for setting these values.
This asks for an underline cursor sized for the boot-time font instead
of various less hard-coded but worse values. I used that think that
the x86 BIOS always gave the same values as the above hard-coding, but
on 1 of my systems it gives the wrong value of base = 1.
The remaining BIOS fields are shift_state and bell_pitch. These are now
consistently not explicitly reinitialized to 0. All sc_get_bios_value()
functions except x86's are now empty, and the only useful thing that x86
returns is shift_state. This really belongs in atkbdc, but heavier
use of the BIOS to read the more useful typematic rate has been removed
there. fb still makes much heavier use of the BIOS.
was aliased to a vt sequence, causing and fixing various bugs.
For syscons, this restores support for arg 2 which sets blinking block
too forcefully, and restores bugs for arg 0 and 1. Arg 2 is used for
vs in the cons25 entry in termcap, but I've never noticed an application
that uses this. The bugs involve replacing local settings by global
ones and need better handling of defaults to fix.
For vt, this requires moving the aliasing code from teken to vt where
it belongs. This sequences is very important for cons25 compatibility
in vt since it is used by the cons25 termcap entries for ve, vi and
vs. vt can't properly support vs for either cons25 or xterm since it
doesn't support blinking. For xterm, the termcap entry for vs asks
for something different using 12;25h instead of 25h.
Rename C25CURS for this to C25LCT and change its description to be closer
to echoing the old comment about it. CURS is too generic.
Fix missing syscons escape sequence for setting the global cursor shape
(and type). Only support this in syscons since vt can't emulate anything
in it.
It should toggle between 2 states, but it used a cut-down version of
support for a related 3-state syscons escape sequence and inherited
bugs from that. The usual misbehaviour was that hiding and showing
the cursor reset it to a global default.
Support for the 3-state sequence remains broken by aliasing to the 2-state
sequence. This works better but incompatibly for the 2 cases that it
supports.
but it was actually extended then and it is still used (just once) in
/usr/src by its primary user (vidcontrol), while its replacement is
still not used in /usr/src.
yokota became inactive soon after deprecating CONS_CURSORTYPE (this
was part of a large change to make cursor attributes per-vty).
vidcontrol has incomplete support even for the old ioctl. I will
update it soon. Then there are many broken escape sequences to fix.
This is just to prepare for setting cursor colors using vidcontrol.
code was used, so the lightness bit was not flipped, so the flipping
was unnecessarily null in some cases. E.g., the unusal color scheme
of lightwhite on white (white = lightgrey in kernelspeak) is not
completely unusable, except null flipping of it gave no visible marks
for cut marking. Now flipping it works in pixel mode only.
Fix text cursor attribute adjustment over cut marking in text mode for
the usual cursor type (non-blinking full block). Apply the flipping
for cut marking first and adjust that instead of vice versa. This
gives a uniform color scheme for the usual text cursor type in text
mode: a white block background with no change to the character
foreground except for variations to avoid collisions. The old order
gave a white character fg with no change in the bg in non-colliding
cases. Versions before r316636 changed the bg to the non-cut-marked
one about half the time using a saveunder bug; this accidentally gave
something resembling a block cursor half the time.
text cursors to functions so that it is easier to fix and improve.
This commit doesn't fix anything except for removing unnecessary
complications and adding comments.
to choose the best one.
The old 9x13 cursor was was sort of correct for CGA 640x200 text mode,
but distorted for all other modes. This mode is still available on
all systems with VGA, but stopped being useful in ~1985. It has very
unsquare pixels with an aspect ratio of 240:100 on 4:3 monitors. On
16:9 monitors, the unsquareness in this mode is reduced to only 180:100
iff the monitor stretches the pixels to the full screen.
Newer modes and systems have smaller distortions, but with many more
variations. Square pixels first became common with VGA 640x480 mode
on 4:3 monitors. However, standard VGA text mode also has 9-bit wide
characters and only 25 lines, so it has 720x400 pixels. This has
unsquare pixels with an aspect ratio of 135:100 on 4:3 monitors. On
16:9 monitors, it gives almost-square pixels with an aspect ration of
101:100 iff the monitor stretches, but in modes that were square on
4:3 monitors square similar monitor stretching breaks the squareness.
Guess the physical aspect ratio using heuristics. The old version of
X that I use is further from doing this using info from PnP monitors
that is unavailable in syscons (X doesn't understand if the monitor
is doing stretching and doesn't even understand how its its own mode
changes affect the pixel size). Monitors with aspect ratio control
should be configured to _not_ stretch 4:3 modes to 16:9. Otherwise,
use the machdep.vga_aspect_scale sysctl to compensate. Only 1 of my
4 monitors/laptops requires this. It always stretches to 16:9.
The mouse data has new aspect ratio fields for selecting the best
cursor and a new name field for display in debugging messages.
Selecting the mouse cursor is now a slow operation so it is not done
for every drawing of the cursor. To avoid a new initialization method,
it is done whenever the text cursor is set or changed. Also remove
dead code in settings of text cursors.
Use larger mouse cursors (sometimes the full 10x16 one) for 8x8 fonts
in cases where this works better (mostly in graphics mode).
To mostly fix distortion of mouse cursors by non-square pixels, I
needed 8 variants of the same cursor shape for large fonts and
another 7 variants for small fonts. Some variants are shared,
leaving only 13 variants in 26 glyphs altogether. Keep these in
the BDF source file cursor.bdf. cursor.bdf has another 5 unused
experimental cursors in 10 glyphs. cursor.awk is a simple awk
script for converting this and similar bdf files into C declarations
for copying into scvgarndr.c. syscons doesn't use any of this yet.
colors.
Colors are still hard-coded as 15 (normally lightwhite) for the interior
and 0 (normally black) for the border, but these are now values used in
2 expressions instead of built in to the algorithm. The algorithm used
a fancy and/or method, but this gives no control over the colors except
and'ing all color planes off gives black and or'ing all color planes on
gives lightwhite. Just draw the border and interior in separate colors
using the same method as for characters, including its complications to
optimize for VGA adaptors. Optimization is not really needed here, but
for the VGA case it avoids being slower than the and/or method. The
optimization is worth about 30%.
remove the former.
All other EGA/VGA methods were already shared, with VGA-only features
mostly not used and no decisions in inner loops to optimize fof VGA,
but this method was split up because it is the only important one and
using VGA methods if possible is about twice as fast. The speed is
mostly not from splitting to reduce branches but from doing half as
many bus accesses, so make this easier to maintain by not splitting.
There is now 1 extra branch in an inner loop where it costs less than
1% of the bus access overhead on Haswell even if the compiler schedules
it poorly.
vga planar method (for testing that was supposed to be local that the
former still works). The ega method works on vga but is about twice
as slow. The vga method doesn't work on ega.
Optimize the main vga planar method a little. For changing the
background color (which was otherwise optimized better than most
things), don't switch the write mode from 3 to 0 just to select
the pixel mask of 0xff obscurely by writing 0. Just write 0xff
directly.
a pointer to the main ega drawing method which is misoptimized be in
a different function than the main vga planar mode drawing method.
Vga initialization handles everything with no extra code except for
selecting the different function.
corresponding to the gaps between characters. This fixes distortion
of the cursor due to expanding it across the gaps.
Again for character width 9, when the cursor characters are not in the
graphics range (0xb0-0xdf), the gaps were always there (filled in the
background color for the previous char). They still look strange, but
don't cause distortion. When the cursor characters are in the graphics
range, the gaps are filled by repeating the previous line. This gives
distortion with cilia. Removing vertical lines reduces the distortion
to vertical cilia.
Move the default for the cursor characters out of the graphics range.
With character width 9, this gives gaps instead of distortion and
other problems. With character width 8, it just fixes a smaller set
of other problems. Some distortion and other problems can be recovered
using vidcontrol -M. Presumably the default was to fill the gaps
intentionally, but it is much better to leave gaps. The gaps can even
be considered as a feature for text processing -- they give sub-pointers
to character boundaries. The other problems are: (1) with character
width 9, characters near the cursor are moved into the graphics range
and thus distorted if any of their 8th bits is set; (2) conflicts with
national characters in the graphics range.
The default range for the graphics cursor characters is now 8-11. This
doesn't conflict with anything, since the glyphs for the characters in
this range are unreachable.
Use the 10x16 mouse cursor in text mode too (if the font size is >= 14).
When the character width is 9, removal of 1 or 2 vertical lines makes
10x16 cursor no wider than the 9x13 one usually was. We could even
handle cursors 1 pixel wider in 2 character cells and gaps without
more clipping than given by the gaps (the worst case is 1 pixel in the
left cell, 1 removed in the middle gap, 8 in the right cell and 1
removed in the right gap. The pixel in the right gap is removed so
it doesn't matter if it is in the font).
When the character width is 8, we now clip the 10-wide cursor by 1
pixel in the worst case. This clipping is usually invisible since it
is of the border and and the border usually merges with the background
so is invisible. There should be an option to use reverse video to
highlight the border and its tip instead of the interior (graphics
mode can do better using separate colors). This needs the 9x13 cursor
again.
Ideas from: ache (especially about the bad default character range)
mode.
Use the general DRAWPIXEL() macro with its bigger case statement
(twice) instead of our big case statement (once). DRAWPIXEL() is more
complicated since it is not missing support for depth 24 or
complications for colors in depth 16 (we currently hard-code black and
white so the complications for colors are not needed). DRAWPIXEL()
also does the bpp calculation in the inner loop. Compilers optimize
DRAWPIXEL() well enough, and the main text drawing method always
depended on this. In direct mode, mouse cursor drawing is now similar
to normal text drawing except it draws in 2 hard-coded colors instead
of 1 variable color.
This also fixes a nested hard-coding of colors. DRAWPIXEL() uses the
palette in all cases, but the direct code didn't use the palette for
its hard-coded black. This only had an effect in depth 8, since
changing the palette is not supported in other depths.
direct mode renderer. I thought that reads were not much slower than
writes, so that the method only tripled the time for the whole function,
but I recently measured that video memory reads can be up to 53 times
slower than writes in tighter loops than here. Loop overheap here
reduces the multiplier to only 16-20 on Haswell.
Start cleaning up and fixing larger bugs in this function. Only replace
the 22-line removal loop by a 3-line one for now, since adjusting the
old loop would have required many palette calculations which are better
done in the DRAW_PIXEL() macro. This also fixes missing support for
depth 24, but only for removal.
Removal is currently sloppy at the right bottom corner. It sometimes
leaks border color into the text window. This is soon cleaned up by the
caller. The planar renderer has complications to clip at the corner.
modes if the font size is >= 14.
This is the X cursor XC_left_ptr (#68) (glyph #45 in an X cursor font).
Also found in vt. The old 9x13 cursor is the 10x16 one trimmed not very
well.
8x8 fonts need a smaller cursor instead of a larger one, except when
the pixel size is small. Text mode is still limited to width and height
1 more than the font (so the 9x13 is already 4 pixels too high for it).
access it via pointers (still to only 1 instance, now with a less
generic name).
Restructure the "and" and "or" masks as border and interior masks
(where the "and" mask was for the union of the border and the interior).
"and" and "or" were only a detail in a not very good implementation,
and after fixing that the union was only used to calculate the border
at runtime.
Use the metric data in more places to clip to active pixels earlier.
mode.
Direct mode always supported widths up to 32, except for its hard-coded
16s matching the pixmap size. Text mode is still limited to 9 its 2x2
character cell method and missing adjustments for the gap between
characters, if any.
Cursor heights can be almost anything in graphics modes.
much as possible, by avoiding null ANDs and ORs to the frame buffer.
Mouse cursors are fairly sparse, especially for their frame. Pixels
are written in groups of 8 in planar mode and the per-group sparseness
is not as large, but it still averages about 40% with the current
9x13 mouse cursor. The average drawing time is reduced by about this
amount (from 22 usec constant to 12.5 usec average on Haswell).
This optimization is relatively larger with larger cursors. Width 10
requires 6 frame buffer accesses per line instead of 4 if not done
sparsely, but rarely more than 4 if done sparsely.
mode.
Don't manually unroll the 2 inner loops. On Haswell, doing so gave a
speedup of about 0.5% (about 4 cycles per iteration out of 1400), but
hard-coded a limit of width 9 and made better better optimizations
harder to see. gcc-4.2.1 -O does the unrolling anyway, unless tricked
with a volatile hack. gcc's unrolling is not very good and gives a
a speedup of about half as much (about 2 cycles per iteration). (All
timing on i386.)
Manual unrolling was only feasible because the inner loop only iterates
once or twice. Usually twice, but a dynamic check is needed to decide,
and was not moved from the second-innermost loop manually or by gcc.
This commit basically adds another dynamic check in the inner loop.
Cursor widths of 10-17 require 3 iterations in the inner loop and this
is not so easy to unroll -- even gcc stops at 2.
the method a lot.
Reduce the AND mask to the complement of the cursor's frame, so that area
inside the frame is not drawn first in black and then in lightwhite. The
AND-OR method is only directly suitable for the text mouse image, since
it doesn't go to the hardware there. Planar mode Mouse cursor drawing
takes 10-20 usec on my Haswell system (approx. 100 graphics accesses
at 130 nsec each), so the transient was not visible.
The method used the fancy read mode 1 and its color compare and color
don't care registers with value 0 in them so that all colors matched.
All that this did was make byte reads of frame buffer memory return 0xff,
so that the x86 case could obfuscate read+write as "and". The read must
be done for its side effect on the graphics controller but is not used,
except it must return 0xff to avoid affecting the write when the write
is obfuscated as a read-modify-write "and". Perhaps that was a good
optimization for 8088 CPUs where each extra instruction byte took as
long as a byte memory access.
Just use read+write after removing the fancy read mode. Remove x86
ifdefs that did the "and". After removing the "and" in the non-x86
part of the ifdefs, fix 4 of 6 cases where the shift was wrong.
in unusual cases. Optimize and significantly clean up removal in this
renderer. Optimize removal in the vga direct renderer.
Removal only needs to be done in the border (the part with pixels) in
both cases. The planar renderer used the condition scp->xoff > 0 to
test whether a right border exists. This actually tests for a left
border, and when the total horizontal border is 8 pixels, rounding gives
only a right border. This was the unusual broken case. An example
is easy to configure using something like "vidcontrol -f 8x16 iso-8x16
-g 79x25 MODE_27".
Optimize the planar case a little by only removing 9x13 active pixels
out of 16x16. Optimize it a lot by not doing anything if there is no
overlap with the border. Don't unroll the main loop or hard-code so
many assumptions about font sizes in it. On my Haswell system, graphics
memory and i/o accesses takes about 520 cycles each so optimizations from
unrolling are in the noise.
Optimize the direct case to not do anything if there is no overlap with
the border. Do a sanity check on the saveunder's coordinates. This
requires a previous change to pass non-rounded coordinates.
The previous commit also fixed the coordinates passed to the mouse
removal renderer. The coordinates were rounded down to a character
boundary, and thus essentially unusable. The renderer had to keep
track of the previous position, or clear a larger area. The latter
is only safe in the border, which is all that needs special handling
anyway.
I think no renderer depends on the bug. They have the following
handling:
- gfb sparc64: this seems to assume non-rounded coordinates
- gfb other: does nothing (seems to be missing border handling)
- vga text: does nothing (doesn't need border handling)
- vga planar: clears extras in the border, with some bugs. The fixes
will use the precise coordinates to optimize.
- vga direct: clears at the previous position with no check that it
is active, and clears everything. Checking finds this bug.
- others: are there any?
reduce hard-coded assumptions on font sizes so that the cursor size
can be more independent of the font size. Moving the mouse in the
buggy mode left trails of garbage.
The mouse cursor currently has size 9x13 in all modes. This can occupy
2x3 character cells with 8x8 fonts, but the algorithm was hard-coded
for only 2x2 character cells. Rearrange to hard-code only a maximum
cursor size (now 10x16) and to not hard-code in the logic. The number
of cells needed is now over-estimated in some cases.
2x3 character cells should also be used in text mode with 8x8 fonts
(except with large pixels, the cursor size should be reduced), but
hard-coding for 2x2 in the implementation makes it not very easy to
expand, and it practice it shifts out bits to reduce to 2x2.
In graphics modes, expansion is easier and there is no shifting out
for 9x13 cursors (but 9 is a limit for hard-coding for 2 8-bit VGA
cells wide). A previous commit removed the same buggy hard-coding for
removal at a lower level in planar mode. Another previous commit fixed
the much larger code for lower-level removal in direct mode; this is
independent of the font size so worked for 8x8 fonts. Text mode always
depended on the higher-level removal here, and always worked since
everything was hard-coded consistently for 2x2 character cells.
scteken_init(). Move the internals of scteken_sync() into a local
function to help do this.
scteken_init() reset or adjusted the default attribute and screen
position at least 3 and 5 times, respectively. Warm init shouldn't
do any more than reset the "input" state.
(scterm-sc.c (which still works after minor editing), only resets
the escape state and the saved cursor position, and then does a
nearly-null sync of the current color.)
This mainly broke mode changes, and was most noticeable when the
background color is not teken's default (usually black). Then the
screen gets cleared in the wrong color. vidcontrol restores the
default normal attribute and tries to restore the default reverse
attribute. vidcontrol doesn't clear the screen again after restoring
the attribute(s), and it is too late to do it there without flicker.
Now the default normal attribute is restored before the change affects
the rendering.
When the foreground color is not teken's default, clearing with the
wrong attributes gave strange cursor colors for some cursor types.
The default reverse attribute is not restored since it is unsupported.
2/3 of the clobbering was from 2 resetting window resizing calls. The
second one is needed to restore the size, but must not reset. Window
resizing also sanitizes the cursor position, and after the main reset
resets the window size, the cursor row would often be adjusted from
24 to 23 if it were not already reset to 0. scteken_sync() is good
for restoring the window size and the cursor position in the correct
order, but was unusable at init time since scp->ts is not always
initialized then. Adjust to use its internals.
I didn't notice any problems from the cursor reset. The cursor should
be reset, and a previous fix was to reset it consistently a little
later.
Doing nothing for warm init works almost as well, if not better. It
is not very useful to reset the escape state for mode changes, since
the reset is especially likely to be null then. The escape state is
most likely to be non-initial and corrupted by its most normal uses
-- sloppy non-atomic output where a context switch or just mixing
stdout with stderr splits up escape sequences.
like I hoped, since they are needed for removing parts over the border.
Continue fixing bugs in them.
In the vga planar mode renderer, remove removal of the part of the
image over the text window. This was hard-coded for nearly 8x16 fonts
and in practice didn't remove enough for 8x8 fonts. This used the
wrong attribute over cutmarked regions. The caller refreshes with the
correct attribute later, so the attribute bug only caused flicker.
The caller uses the same hard-coding, so the refreshes fix up all the
spots with the wrong attribute, but keep missing the missed spots.
This still gives trails of bits of cursors for cursor motions in the
affected configurations (mainly depth 4 modes with 8x8) fonts. 8x14
fonts barely escape the problem since although the cursor is drawn
as 16x16, its active part is only 9x13 and the active part fits in
the hard-coded 2x2 character cell window for 8x14 fonts. 8x8 fonts
need a 2x3 window.
In the fb non-sparc64 renderer, the buggy image removal was buggier
and was already avoided by returning before it. Remove it completely
and fix nearby style bugs. It was essentially the same as for the vga
planar mode renderer (obfuscated by swapping x and y). This was buggier
since fb should handle more types of hardware so the hard-coding is
wronger.
The remaining fb image removal is also buggier. It never supported
software cursors drawn into the border, and the hardware cursor is
probably broken by other bugs to be fixed soon.
(that is, in all supported 8, 15, 16 and 24-color modes). Moving the
mouse cursor while holding down a button (giving cut marking) left a
trail of garbage from misremoved mouse cursors (usually colored
rectangles and not cursor shapes). Cases with a button not held down
worked better and may even have worked.
No renderer support for removing (software) mouse cursors is needed
(and many renderers don't have any), since sc_remove_mouse_image()
marks for update the region containing the image and usually much
more. The mouse cursor can be (partially) over as many as 4 character
cells, and removing it in only the 1-4 cells occupied by it would be
best for efficiency and for avoiding flicker. However,
sc_remove_mouse_image() can only mark a single linear region and
usually marks a full row of cells and 1 more to be sure to cover the
4 cells. It always does this, so using the special rendering method
just wastes even more time and gives even more flicker. The special
methods will be removed soon.
The general method always works. vga_pxlmouse_direct() appeared to
defer to it by returning immediately if !on. However,
vga_pxlmouse_direct() actually did foot-shooting using a disguised
saveunder method. Normal order near a mouse move is:
(1) remove the mouse cursor in the renderer (optional)
(2) remove the mouse cursor again and refresh the screen over the
mouse cursor and much more from the vtb. When the mouse has
actually moved and a button is down, many attributes in this
region are changed to be up to date with the new cut marking
(3) draw the keyboard cursor again if it was clobbered by the update
(4) draw the mouse cursor image in its new position.
The bug was to remove the mouse cursor again in step (4), before the
drawing it again in (4), using a saveunder that was valid in step (1)
at best. The quick fix is to use the saveunder in step (1) and not
in step (4). Using it in step (4) also used it before it was
initialized, initially and after mode and screen switches.
in the vga renderer. Removal used stale attributes and didn't try to
merge with the current attribute for cut marking, so special rendering
of cut marking was lost in many cases. The gfb renderer is too broken
to support special rendering of cut marking at all, so this change is
supposed to be just a style fix for it. Remove all traces of the
saveunder method which was used to implement this bug.
Fix drawing of the cursor image in text mode, only in the vga
renderer. This used a stale attribute from the frame buffer instead
of from the saveunder, but did merge with the current attribute for
cut marking so it caused less obvious bugs (subtle misrendering for
the character under the cursor).
The saveunder method may be good in simpler drivers, but in syscons
the 'under' is already saved in a better way in the vtb. Just redraw
it from there, with visible complications for cut marking and
invisible complications for mouse cursors. Almost all drawing
requests are passed a flag 'flip' which currently means to flip to
reverse video for characters in the cut marking region, but should
mean that the the characters are in the cut marking regions so should
be rendered specially, preferably using something better than reverse
video. The gfb renderer always ignores this flag. The vga renderer
ignored it for removal of the text cursor -- the saveunder gave the
stale rendering at the time the cursor was drawn. Mouse cursors need
even more complicated methods. They are handled by drawing them last
and removing them first. Removing them usually redraws many other
characters with the correct cut marking (but transiently loses the
keyboard cursor, which is redrawn soon). This tended to hide the
saveunder bug for forward motions of the keyboard cursor. But slow
backward motions of the keyboard cursor always lost the cut marking,
and fast backwards motions lost in for about 4 in every 5 characters,
depending on races with the scrn_update() timeout handler. This is
because the forward motions are usually into the region redrawn for
the mouse cursor, while backwards motions rarely are.
Text cursor drawing in the vga renderer used also used a
possibly-stale copy of the character and its attribute. The vga
render has the "optimization" of sometimes reading characters from the
screen instead of from the vtb (this was not so good even in 1990 when
main memory was only a few times faster than video RAM). Due to care
in update orders, the character is never stale, but its attribute
might be (just the cut marking part, again due to care in order).
gfb doesn't have the scp->scr pointer used for the "optimization", and
vga only uses this pointer for text mode. So most cases have to
refresh from the vtb, and we can be sure that the ordering of vtb
updates and drawing is as required for this to work.
position. Especially the screen size, and potentially everything except
the input state and attributes. Do this by changing the cursor position
setting method to a general syncing method.
Use proper constructors instead of copying to create kernel terminal
contexts. We really want clones and not new instances, but there is
no method for cloning and there is nothing in the active instance that
needs to be cloned exactly.
Add proper destructors for kernel terminal contexts. I doubt that the
destructor code has every been reached, but if it was then it leaked the
memory of the clones.
Remove freeing of statically allocated memory for the non-kernel terminal
context for the same terminal as the kernel. This is in the nearly
unreachable code. This used to not happen because delicate context
swapping made the user context use the dynamic memory and kernel
context the static memory. I didn't restore this swapping since it
would have been unnatural to have all kernel contexts except 1 dynamic.
The constructor for terminal context has bad layering for reasons
related to the bug. It has to return static memory early before
malloc() works. Callers also can't allocate memory until after the
first constructor selects an emulator and tells upper layers the size
of its context. After that, the cloning hack required the cloning
code to allocate the memory, but for all other constructors it would
be better for the terminal layer to allocate and deallocate the
memory in all cases.
Zero the memory when allocating terminal contexts dynamically.
it to a separate state for each CPU.
Terminal "input" is user or kernel output. Its state includes the current
parser state for escape sequences and multi-byte characters, and some
results of previous parsing (mainly attributes), and in teken the cursor
position, but not completed output. This state must be switched for kernel
output since the kernel can preempt anything, including itself, and this
must not affect the preempted state more than necessary. Since vty0 is
shared, it is necessary to affect the frame buffer and cursor position and
history, but escape sequences must not be affected and attributes for
further output must not be affected.
This used to work. The syscons terminal state contained mainly the parser
state for escape sequences and attributes, but not the cursor position,
and was switched. This was first broken by SMP and/or preemptive kernels.
Then there should really be a separate state for each thread, and one more
for ddb, or locking to prevent preemption. Serialization of printf() helps.
But it is arcane that full syscons escape sequences mostly work in kernel
printf(), and I have never seen them used except by me to test this fix.
They worked perfectly except for the races, since "input" from the kernel
was not special in any way.
This was broken to use teken. The general switch was removed, and the
kernel normal attribute was switched specially. The kernel reverse
attribute (config option SC_CONS_REVERSE_ATTR) became unused, and is
still unusable because teken doesn't support default reverse attributes
(it used to only be used via the ANSI escape sequence to set reverse
video).
The only new difficulty for using teken seems to be that the cursor
position is in the "input" state, so it must be updated in the active
input state for each half of the switch. Do this to complete the
restoration.
The per-CPU state is mainly to make per-CPU coloring work cleanly, at
a cost of some space. Each CPU gets its own full set of attribute
(not just the current attribute) maintained in the usual way. This
also reduces races from unserialized printf()s. However, this gives
races for serialized printf()s that otherwise have none. Nothing
prevents the CPU doing the a printf() changing in the middle of an
escape sequence.
for vt. Restore syscons' rendering of background (bg) brightness as
foreground (fg) blinking and vice versa, and add rendering of blinking
as background brightness to vt.
Bright/saturated is conflated with light/white in the implementation
and in this description.
Bright colors were broken in all cases, but appeared to work in the
only case shown by "vidcontrol show". A boldness hack was applied
only in 1 layering-violation place (for some syscons sequences) where
it made some cases seem to work but was undone by clearing bold using
ANSI sequences, and more seriously was not undone when setting
ANSI/xterm dark colors so left them bright. Move this hack to drivers.
The boldness hack is only for fg brightness. Restore/add a similar hack
for bg brightness rendered as fg blinking and vice versa. This works
even better for vt, since vt changes the default text mode to give the
more useful bg brightness instead of fg blinking.
The brightness bit in colors was unnecessarily removed by the boldness
hack. In other cases, it was lost later by teken_256to8(). Use
teken_256to16() to not lose it. teken_256to8() was intended to be
used for bg colors to allow finer or bg-specific control for the more
difficult reduction to 8; however, since 16 bg colors actually work
on VGA except in syscons text mode and the conversion isn't subtle
enough to significantly in that mode, teken_256to8() is not used now.
There are still bugs, especially in vidcontrol, if bright/blinking
background colors are set.
Restore XOR logic for bold/bright fg in syscons (don't change OR
logic for vt). Remove broken ifdef on FG_UNDERLINE and its wrong
or missing bit and restore the correct hard-coded bit. FG_UNDERLINE
is only for mono mode which is not really supported.
Restore XOR logic for blinking/bright bg in syscons (in vt, add
OR logic and render as bright bg). Remove related broken ifdef
on BG_BLINKING and its missing bit and restore the correct
hard-coded bit. The same bit means blinking or bright bg depending
on the mode, and we want to ignore the difference everywhere.
Simplify conversions of attributes in syscons. Don't pretend to
support bold fonts. Don't support unusual encodings of brightness.
It is as good as possible to map 16 VGA colors to 16 xterm-16
colors. E.g., VGA brown -> xterm-16 Olive will be converted back
to VGA brown, so we don't need to convert to xterm-256 Brown. Teken
cons25 compatibility code already does the same, and duplicates some
small tables. This is mostly for the sc -> te direction. The other
direction uses teken_256to16() which is too generic.
