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path: root/sys/dev/syscons/syscons.c
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2025-06-17Internal scheduling priorities: Always use symbolic onesOlivier Certner
Replace priorities specified by a base priority and some hardcoded offset value by symbolic constants. Hardcoded offsets prevent changing the difference between priorities without changing their relative ordering, and is generally a dangerous practice since the resulting priority may inadvertently belong to a different selection policy's range. Since RQ_PPQ is 4, differences of less than 4 are insignificant, so just remove them. These small differences have not been changed for years, so it is likely they have no real meaning (besides having no practical effect). One can still consult the changes history to recover them if ever needed. No functional change (intended). MFC after: 1 month Event: Kitchener-Waterloo Hackathon 202506 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D45390
2025-06-11machine/stdarg.h -> sys/stdarg.hBrooks Davis
Switch to using sys/stdarg.h for va_list type and va_* builtins. Make an attempt to insert the include in a sensible place. Where style(9) was followed this is easy, where it was ignored, aim for the first block of sys/*.h headers and don't get too fussy or try to fix other style bugs. Reviewed by: imp Exp-run by: antoine (PR 286274) Pull Request: https://github.com/freebsd/freebsd-src/pull/1595
2025-05-31syscons(4): Fix a typo in a source code commentGordon Bergling
- s/contants/constants/ MFC after: 3 days
2023-08-16sys: Remove $FreeBSD$: one-line .c patternWarner Losh
Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/
2023-03-01syscons: whack __mips__ leftoversMateusz Guzik
Sponsored by: Rubicon Communications, LLC ("Netgate")
2023-02-14sys/kbio.h: make pre-unicode keymap support optionalStefan Eßer
FreeBSD-9 had introduced support for the full set of Unicode characters to the parsing and processing of keymap character tables. This support has been extended to cover the table for accented characters that are reached via dead key combinations in FreeBSD-13.2. New ioctls have been introduced to support both the pre-Unicode and the Unicode formats and keyboard drivers have been extended to support those ioctls. This commit makes the ABI compatibility functions in the kernel optional and dependent on COMPAT_FREEBSD13 in -CURRENT. The kbdcontrol command in -CURRENT and 13-STABLE (before 13.2) has been made ABI compatible with old kernels to allow a new world to be run on an old kernel (that does not have full Unicode support for keymaps). This commit is not to merged back to 12-STABLE or 13-STABLE. It is part of review D38465, which has been split into 3 separate commits due to different MFC and life-time requirements of either commit. Approved by: imp Differential Revision: https://reviews.freebsd.org/D38465
2023-02-06Support Unicode characters in keymap dead key tablesStefan Eßer
Support for Unicode characters had been added to the keyboard code, but there are keymaps that have accented characters accessed via dead key combinations, and those were still restricted to 8 bit codes. This update to kbd.c adds support for Unicode characters and compatibility code that allows a kbdcontrol command built from kbio.h without these patches to work on a new kernel. Compatibility code that allows a new kbdcontrol binary running on an old kernel to load and display the dead key map will be committed in a separate commit. Reviewed by: imp, brooks Approved by: brooks MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D38381
2021-11-03sysbeep: Adjust interface to take a duration as a sbtWarner Losh
Change the 'period' argument to 'duration' and change its type to sbintime_t so we can more easily express different durations. Reviewed by: tsoome, glebius Differential Revision: https://reviews.freebsd.org/D32619
2020-09-01syscons: clean up empty lines in .c and .h filesMateusz Guzik
Notes: svn path=/head/; revision=365088
2020-02-26Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)Pawel Biernacki
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are still not MPSAFE (or already are but aren’t properly marked). Use it in preparation for a general review of all nodes. This is non-functional change that adds annotations to SYSCTL_NODE and SYSCTL_PROC nodes using one of the soon-to-be-required flags. Mark all obvious cases as MPSAFE. All entries that haven't been marked as MPSAFE before are by default marked as NEEDGIANT Approved by: kib (mentor, blanket) Commented by: kib, gallatin, melifaro Differential Revision: https://reviews.freebsd.org/D23718 Notes: svn path=/head/; revision=358333
2020-02-03Remove sparc64 kernel supportWarner Losh
Remove all sparc64 specific files Remove all sparc64 ifdefs Removee indireeect sparc64 ifdefs Notes: svn path=/head/; revision=357455
2020-01-12Add KERNEL_PANICKED macro for use in place of direct panicstr testsMateusz Guzik
Notes: svn path=/head/; revision=356655
2019-12-23syscons: drop keyboard index from softcKyle Evans
Analysis seems to reveal that sc->keyboard >= 0 implies sc->kbd != NULL and there's no such scenario where sc->kbd is set (and theoretically used to rebuild sc->keyboard) with the keyboard unavailable. Drop the index softc. The index is only explicitly needed in few places, in which case we can just as easily grab it from sc->kbd. There's no need for keeping sc->kbd and sc->keyboard in sync when it can be readily accomplished with just the former. Notes: svn path=/head/; revision=356043
2019-12-10Use callout_func_t instead of the deprecated timeout_t.John Baldwin
Reviewed by: kib, imp Differential Revision: https://reviews.freebsd.org/D22752 Notes: svn path=/head/; revision=355601
2019-12-03syscons.c: clang-format pass to reduce style inconsistenciesKyle Evans
This was purely automatically massaged... some parts are still imperfect, but this is close enough to make it more readable/easy to work on. Unfortunately the vt/syscons/kdb situation slightly complicates changes to tty locking, so some work will need to be done to remediate that. Notes: svn path=/head/; revision=355316
2019-01-30i386: Merge PAE and non-PAE pmaps into same kernel.Konstantin Belousov
Effectively all i386 kernels now have two pmaps compiled in: one managing PAE pagetables, and another non-PAE. The implementation is selected at cold time depending on the CPU features. The vm_paddr_t is always 64bit now. As result, nx bit can be used on all capable CPUs. Option PAE only affects the bus_addr_t: it is still 32bit for non-PAE configs, for drivers compatibility. Kernel layout, esp. max kernel address, low memory PDEs and max user address (same as trampoline start) are now same for PAE and for non-PAE regardless of the type of page tables used. Non-PAE kernel (when using PAE pagetables) can handle physical memory up to 24G now, larger memory requires re-tuning the KVA consumers and instead the code caps the maximum at 24G. Unfortunately, a lot of drivers do not use busdma(9) properly so by default even 4G barrier is not easy. There are two tunables added: hw.above4g_allow and hw.above24g_allow, the first one is kept enabled for now to evaluate the status on HEAD, second is only for dev use. i386 now creates three freelists if there is any memory above 4G, to allow proper bounce pages allocation. Also, VM_KMEM_SIZE_SCALE changed from 3 to 1. The PAE_TABLES kernel config option is retired. In collaboarion with: pho Discussed with: emaste Reviewed by: markj MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D18894 Notes: svn path=/head/; revision=343567
2018-08-26Remove the Yarrow PRNG algorithm option in accordance with due noticeMark Murray
given in random(4). This includes updating of the relevant man pages, and no-longer-used harvesting parameters. Ensure that the pseudo-unit-test still does something useful, now also with the "other" algorithm instead of Yarrow. PR: 230870 Reviewed by: cem Approved by: so(delphij,gtetlow) Approved by: re(marius) Differential Revision: https://reviews.freebsd.org/D16898 Notes: svn path=/head/; revision=338324
2018-06-02Improve defaults for per-CPU kernel console colors, especially with 2Bruce Evans
or 4 CPUs. Add a compile-time option SC_KERNEL_CONS_ATTRS to control the defaults. Default to color numbers in reverse order to CPU numbers (instead of in the same order with white first and wrapping to dark grey), so that the brightest bright colors are used first. Don't use dark grey at all; replace it by dark green. Syscons has too many compile-time options, but this one is needed in in case the defaults give something like white on white, or the user really hates this feature and can't wait to turn it off in rc. MFC after: next release? Notes: svn path=/head/; revision=334530
2018-06-02Use per-CPU attributes earlier.Bruce Evans
The per-CPU ts is not initialized early, so the global kernel ts is used early, but it ony has 1 (normal) attribute. Switch this to the per-CPU attribute. The difference is most visible with EARLY_AP_STARTUP. Change to using the curcpu macro instead of PCPU_GET(cpuid) in 2 places for the above and in 1 other place in my old code in syscons. The function-like spelling is perhaps better for indicating that curcpu is volatile (unlike curthread), but for CPU attributes volatility is a feature. Notes: svn path=/head/; revision=334529
2018-06-02Fix low-level locking during panics.Bruce Evans
The SCHEDULER_STOPPED() hack breaks locking generally, and mtx_trylock_*() especially. When mtx_trylock_*() returns nonzero, naive code version here trusts it to have worked. But when SCHEDULER_STOPPED() is true, mtx_trylock_*() returns 1 without doing anything. Then mtx_unlock_*() crashes especially badly attempting to unlock iff the error is detected, since mutex unlocking functions don't check SCHEDULER_STOPPED(). syscons already didn't trust mtx_trylock_spin(), but it was missing the logic to turn on sp->kdb_locked when turning off sp->mtx_locked during panics. It also used panicstr instead of SCHEDULER_LOCKED because I thought that panicstr was more fragile. They only differ for a window of lines in panic(), and in broken cases where stop_cpus_hard() in panic() didn't work. Notes: svn path=/head/; revision=334526
2018-04-13i386 4/4G split.Konstantin Belousov
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 Notes: svn path=/head/; revision=332489
2018-04-06Move most of the contents of opt_compat.h to opt_global.h.Brooks Davis
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 Notes: svn path=/head/; revision=332122
2018-03-22Revert r331298Warner Losh
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 Notes: svn path=/head/; revision=331359
2018-03-21Unlock giant when calling shutdown_nice()Warner Losh
Notes: svn path=/head/; revision=331298
2017-11-27sys/dev: further adoption of SPDX licensing ID tags.Pedro F. Giffuni
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. Notes: svn path=/head/; revision=326255
2017-08-25Fix bugs in (mostly) not-yet-activated parts of early/emergency output:Bruce Evans
- 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. Notes: svn path=/head/; revision=322884
2017-08-25Support setting the colors of cursors for the VGA renderer.Bruce Evans
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. Notes: svn path=/head/; revision=322878
2017-08-25Oops, the previous commit was missing 1 line.Bruce Evans
Notes: svn path=/head/; revision=322870
2017-08-25Fix missing switching of the terminal emulator when switching theBruce Evans
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. Notes: svn path=/head/; revision=322869
2017-08-19Fix setting of defaults for the text cursor.Bruce Evans
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. Notes: svn path=/head/; revision=322709
2017-08-19Rename curr_curs_attr to base_curr_attr. The actual current cursorBruce Evans
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. Notes: svn path=/head/; revision=322708
2017-08-19Use better hard-coded defaults for the cursor shape, and remove nearbyBruce Evans
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. Notes: svn path=/head/; revision=322705
2017-08-16Undeprecate the CONS_CURSORTYPE ioctl. It was "deprecated" in 2001,Bruce Evans
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. Notes: svn path=/head/; revision=322575
2017-03-29The switch to kernel terminal context needs to update more than the cursorBruce Evans
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. Notes: svn path=/head/; revision=316136
2017-03-26Restore switching to a separate kernel terminal "input" state and extendBruce Evans
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. Notes: svn path=/head/; revision=315984
2017-03-16The previous fix didn't ifdef out enough for sparc64 to actually work.Bruce Evans
Fix this by using more dynamic initialization with simpler ifdefs for the machine dependencies. Find a frame buffer address in a more portable way that at least compiles on sparc64. Notes: svn path=/head/; revision=315390
2017-03-11Add a scteken_set_cursor() (sc to teken) method and use it to fixBruce Evans
some cases of initialization and resetting of the teken cursor position. (This bad name is consistent with others, but it is too easy to confuse with scteken_cursor() which goes in the opposite direction.) The following cases were broken: - for booting without a syscons console, the teken and sc positions for ttyv0 were (0, 0), but are supposed to be somewhere in the middle of the screen (after carefully preserved BIOS and loader messages) (at least if there is no mode switch that loses the messages). - after mode switches, the screen is cleared and the cursor is supposed to be moved to (0, 0), but it was only moved there for sc. The following case was hacked to work: - for booting with a syscons console, it was arranged that scteken_init() for the console could see a nonzero cursor position and adjust, although this broke the sc seeing it in the non-console case above. Notes: svn path=/head/; revision=315065
2017-03-10Start fixing some bugs in attribute handling.Bruce Evans
This change just does cleanups missed in r56043 17 years ago. The default attributes were still stored in structs for the purpose of changing them and passing around pointers to the defaults, but r56043 added another layer that made the defaults invariant and only used for initialization and reset. Just use the defaults directly. This was already done for the kernel defaults. The defaults for reverse attributes aren't actually used, but are ignored in layers that no longer support them. Notes: svn path=/head/; revision=315000
2017-03-10Fix compilation on sparc64. The frame buffer address is in a field thatBruce Evans
is unavailable on sparc64 only. This makes the new ec_putc() a non-op on sparc64 but still calls it. On other non-x86 arches, it should compile but might not work. Reported by: gjb Notes: svn path=/head/; revision=314997
2017-03-04Implement ec_putc() (emergency kernel [syscons] console putc()) and useBruce Evans
it in emergency in sc_cnputc(). Locking fixes in sc_cnputc() previously turned off normal output in near-deadlock conditions and added deferred output which might never be completed. Emergency output goes to the frame buffer using sufficiently atomic non-blocking writes if the console is in text mode (in graphics mode, nothing is done, modulo races setting the graphics mode bit). Screen updates overwrite the emergency output if the emergency condition clears enough to reach them. ec_putc() also works for "early" console output in normal x86 text mode as soon as this mode is initialized (if ever). This uses a hard-coded x86 frame buffer address before cninit() and a hopefully MI address after cninit(). But non-x86 is more likely to not support text mode, when ec_putc() will be null. ec_putc() has no dependencies of syscons before cninit(), and only has them later to track syscons' mode changes. This commit doesn't attach ec_putc() for early use. To test emergency use, put a breakpoint in central syscons output code like sc_puts() and do some user output. The system used to race or deadlock in ddb output soon after entry to ddb. The locking fixes deferred the output until after leaving ddb, so ddb was unusable and you had to try typing c[ontinue] blindly until it exited, or better use a serial console in parallel. Now the output goes to a window in the middle 2/3 of the screen. Scrolling is circular and there is no cursor, but otherwise ec_putc() provides full dumb terminal functionality and very fast output that hides artificates from dumb overwrites. Notes: svn path=/head/; revision=314646
2017-03-04Colorize syscons kernel console output according to a table indexedBruce Evans
by the CPU number. This was originally for debugging near-deadlock conditions where multiple CPUs either deadlock or scramble each other's output trying to report the problem, but I found it interesting and sometimes useful for ordinary kernel messages. Ordinary kernel messages shouldn't be interleaved, but if they are then the colorization makes them readable even if the interleaving is for every character (provided the CPU printing each message doesn't change). The default colors are 8-15 starting at 15 (bright white on black) for CPU 0 and repeating every 8 CPUs. This works best with 8 CPUs. Non-bright colors and nonzero background colors need special configuration to avoid unreadable and ugly combinations so are not configured by default. The next bright color after 15 is 8 (bright black = dark gray) is not very readable but is the only other color used with 2 CPUs. After that the next bright color is 9 (bright blue) which is not much brighter than bright black, but is used with 3+ CPUs. Other bright colors are brighter. Colorization is configured by default so that it gets tested. It can only be turned off by configuring SC_KERNEL_CONS_ATTR to anything other than FG_WHITE. After booting, all colors can be changed using the syscons.kattr sysctl. This is a SYSCTL_OPAQUE, and no utility is provided to change it (sysctl only displays it). The default colors work in all VGA modes that I could test. In 2-color graphics modes, all 8 bright colors are displayed as bright white, so the colorization has no effect, but anything with a nonzero background gives white on white unless the foreground is zero. I don't have an mono or VGA grayscale hardware to test on. Support for mono mode seems to have never worked right in syscons (I think bright white gives white underline with either bold or bright), but VGA grayscale should work better than 2-color graphics. Notes: svn path=/head/; revision=314641
2017-01-28Remove pc98 support completely.Yoshihiro Takahashi
I thank all developers and contributors for pc98. Relnotes: yes Notes: svn path=/head/; revision=312910
2016-09-01The log message for the previous commit didn't mention the most theBruce Evans
important detail that sc_cngetc() now opens and closes the keyboard on every call again. This was moved from sc_cngetc() to scn_cngrab/ ungrab() in r228644, but the change wasn't quite complete. After fixes for nesting in kbdd_poll() in ukbd and kbdmux, these opens and closes should have no significant effect if done while grabbed. They fix unusual cases when cngetc() is called while not grabbed. This commit is the main fix for screen locking in sc_cnputc(): detect deadlock or likely-deadlock and handle it by buffering the output atomically and printing it later if the deadlock condition clears (and sc_cnputc() is called). The most common deadlock is when the screen lock is held by ourself. Then it would be safe to acquire the lock recursively if the console driver is calling printf() in a safe context, but we don't know when that is. It is not safe to ignore the lock even in kdb or panic mode. But ignore it in panic mode. The only other known case of deadlock is when another thread holds the lock but is running on a stopped CPU. Detect that case approximately by using trylock and retrying for 1000 usec. On a 4 GHz CPU, 100 usec is almost long enough -- screen switches take slightly longer than that. Not retrying at all is good enough except for stress tests, and planned future versions will extend the timeout so that the stress tests work better. To see the behaviour when deadlock is detected, single step through sctty_outwakeup() (or sc_puts() to start with deadlock). Another (serial) console is needed to the buffered-only output, but the keyboard works in this context to continue or step out of the deadlocked region. The buffer is not large enough to hold all the output for this. Notes: svn path=/head/; revision=305231
2016-08-31Add some locking to sc_cngetc().Bruce Evans
Keyboard input needs Giant locking, and that is not possible to do correctly here. Use mtx_trylock() and proceed unlocked as before if we can't acquire Giant (non-recursively), except in kdb mode don't even try to acquire Giant. Everything here is a hack, but it often works. Even if mtx_trylock() succeeds, this might be a LOR. Keyboard input also needs screen locking, to handle screen updates and switches. Add this, using the same simplistic screen locking as for sc_cnputc(). Giant must be acquired before the screen lock, and the screen lock must be dropped when calling the keyboard driver (else it would get a harmless LOR if it tries to acquire Giant). It was intended that sc cn open/close hide the locking calls, and they do for i/o functions functions except for this complication. Non-console keyboard input is still only Giant-locked, with screen locking in some called functions. This is correct for the keyboard parts only. When Giant cannot be acquired properly, atkbd and kbdmux tend to race and work (they assume that the caller acquired Giant properly and don't try to acquire it again or check that it has been acquired, and the races rarely matter), while ukbd tends to deadlock or panic (since it does the opposite, and has other usb threads to deadlock with). The keyboard (Giant) locking here does very little, but the screen locking completes screen locking for console mode except for not detecting or handling deadlock. Notes: svn path=/head/; revision=305121
2016-08-30Start adding locking to sc_cngetc().Bruce Evans
Restore an splx() lost in r228644. We aren't nearly ready to remove spl's. They give hints about missing locking. This lost one was misplaced. Dropping it early for convenience gave race windows for accesses to the fkey buffer. Giant locking accidentally fixed this for non-console cases. Put the spl's around the whole function. Since there are many returns that would need splx() just before them for a direct fix, split the function into a wrapper that does the spl's and a "locked" function that does the work. Return earlier when no keyboard is attached to match the ordering in a planned version. This breaks the dubious feature of returning keys from the fkey buffer after the keyboard has gone away. Losing the keys wouldn't matter, but we keep them too long now. Notes: svn path=/head/; revision=305059
2016-08-29Add screen locking calls to sc cn grab and ungrab. The locking functionsBruce Evans
just use the same mutex locking as sc cn putc so they have the same defects. The locking calls to acquire the lock are actually in sc cn open and close. Ungrab has to unlock, although this opens a race window. Change the direct mutex lock calls in sc cn putc to the new locking functions via the open and close functions. Putc also has to unlock, but doesn't keep the screen open like grab. Screen open and close reduce to locking, except screen open for grab also attempts to switch the screen. Keyboard locking is more difficult and still null, even when keyboard input calls screen functions, except some of the functions have locks too deep to work right. This organization gives a single place to fix some of the locking. Notes: svn path=/head/; revision=305010
2016-08-25Less-quick fix for locking fixes in r172250. r172250 added a secondBruce Evans
syscons spinlock for the output routine alone. It is better to extend the coverage of the first syscons spinlock added in r162285. 2 locks might work with complicated juggling, but no juggling was done. What the 2 locks actually did was to cover some of the missing locking in each other and deadlock less often against each other than a single lock with larger coverage would against itself. Races are preferable to deadlocks here, but 2 locks are still worse since they are harder to understand and fix. Prefer deadlocks to races and merge the second lock into the first one. Extend the scope of the spinlocking to all of sc_cnputc() instead of just the sc_puts() part. This further prefers deadlocks to races. Extend the kdb_active hack from sc_puts() internals for the second lock to all spinlocking. This reduces deadlocks much more than the other changes increases them. The s/p,10* test in ddb gets much further now. Hide this detail in the SC_VIDEO_LOCK() macro. Add namespace pollution in 1 nested #include and reduce namespace pollution in other nested #includes to pay for this. Move the first lock higher in the witness order. The second lock was unnaturally low and the first lock was unnaturally high. The second lock had to be above "sleepq chain" and/or "callout" to avoid spurious LORs for visual bells in sc_puts(). Other console driver locks are already even higher (but not adjacent like they should be) except when they are missing from the table. Audio bells also benefit from the syscons lock being high so that audio mutexes have chance of being lower. Otherwise, console drviver locks should be as low as possible. Non-spurious LORs now occur if the bell code calls printf() or is interrupted (perhaps by an NMI) and the interrupt handler calls printf(). Previous commits turned off many bells in console i/o but missed ones done by the teken layer. Notes: svn path=/head/; revision=304804
2016-08-25Fix logic errors in bounds checks in previous commit. The 2-entry stackBruce Evans
was overrun for grab levels larger than 2. Reported by: pluknet Notes: svn path=/head/; revision=304800
2016-08-24Flesh out the state and flags args to sccnopen(). Set state flags toBruce Evans
indicate (potentially partial) success of the open. Use these to decide what to close in sccnclose(). Only grab/ungrab use open/close so far. Add a per-sc variable to count successful keyboard opens and use this instead of the grab count to decide if the keyboad state has been switched. Start fixing the locking by using atomic ops for the most important counter -- the grab level one. Other racy counting will eventually be fixed by normal mutex or kdb locking in most cases. Use a 2-entry per-sc stack of states for grabbing. 2 is just enough to debug grabbing, e.g., for gets(). gets() grabs once and might not be able to do a full (or any) state switch. ddb grabs again and has a better chance of doing a full state switch and needs a place to stack the previous state. For more than 3 levels, grabbing just changes the count. Console drivers should try to switch on every i/o in case lower levels of nesting failed to switch but the current level succeeds, but then the switch (back) must be completed on every i/o and this flaps the state unless the switch is null. The main point of grabbing is to make it null quite often. Syscons grabbing also does a carefully chosen screen focus that is not done on every i/o. Add a large comment about grabbing. Restore some small lost comments. Notes: svn path=/head/; revision=304773
2016-08-24Reorganise a little to prepare for locking fixes:Bruce Evans
- in sccnopen(), open the keyboard before the screen. The keyboard currently requires Giant (although it must be spinlocked to work correctly as a console), so the previous order would be a LOR if it has any semblance of locking. - add a (currently dummy) state arg to scgetc(). Notes: svn path=/head/; revision=304758