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author | peter <peter@FreeBSD.org> | 2003-07-22 08:15:29 +0000 |
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committer | peter <peter@FreeBSD.org> | 2003-07-22 08:15:29 +0000 |
commit | a05513a73ba4e0fe3feec93bae5b7c009be6b38c (patch) | |
tree | 2ca8a6f06a8c53657f16c6a094344d94c10144f8 /share | |
parent | 7c1e58684a0e6e588206d5592175b02c0211418b (diff) | |
download | FreeBSD-src-a05513a73ba4e0fe3feec93bae5b7c009be6b38c.zip FreeBSD-src-a05513a73ba4e0fe3feec93bae5b7c009be6b38c.tar.gz |
Update npx status.
Reminded by: tjr
Diffstat (limited to 'share')
-rw-r--r-- | share/man/man4/man4.i386/npx.4 | 60 |
1 files changed, 4 insertions, 56 deletions
diff --git a/share/man/man4/man4.i386/npx.4 b/share/man/man4/man4.i386/npx.4 index b91736e..7eea372 100644 --- a/share/man/man4/man4.i386/npx.4 +++ b/share/man/man4/man4.i386/npx.4 @@ -35,24 +35,18 @@ .Os .Sh NAME .Nm npx -.Nd Numeric Processing Extension coprocessor and emulator +.Nd Numeric Processing Extension coprocessor .Sh SYNOPSIS .Cd "device npx" .Cd hint.npx.0.at="nexus" .Cd hint.npx.0.port="0x0F0" .Cd hint.npx.0.flags="0x0" .Cd hint.npx.0.irq="13" -.Pp -For hosts without a FPU coprocessor add: -.Cd "options MATH_EMULATE" -or -.Cd "options GPL_MATH_EMULATE" .Sh DESCRIPTION The .Nm driver enables the use of the system's Numeric Processing Extension -coprocessor, -if one is present. +coprocessor. Numeric processing extensions are present in systems with .Tn 486DX @@ -63,32 +57,8 @@ or coprocessors. The .Nm -driver is required for proper system functioning regardless -of whether or not a NPX is present. -.Pp -If there is no NPX present in the system, the -.Dv MATH_EMULATE -or -.Dv GPL_MATH_EMULATE -option must be defined in the kernel configuration -file. -It will provide support for the instructions normally executed by the NPX. -If there is no NPX in the system and the kernel is not built with math -emulation, the system will not boot. -.Pp -You can choose to use a much more fully-featured math emulator (under the -GPL license) by including the -.Cd "options GPL_MATH_EMULATE" -in your kernel -configuration file instead of the -.Dv MATH_EMULATE -option. -.Pp -The -.Pa GENERIC -kernel configuration uses the -.Dv MATH_EMULATE -option. +driver is required for proper system functioning. +If there is no NPX in the system, the system will not boot. .Pp The flags for .Pa npx0 @@ -101,8 +71,6 @@ do not use the NPX registers to optimize bcopy. do not use the NPX registers to optimize bzero. .It 0x04 do not use the NPX registers to optimize copyin or copyout. -.It 0x08 -use emulator even if hardware FPU is available. .El .Pp The NPX registers are normally used @@ -137,27 +105,7 @@ until later in the bootstrap when .Pa npx0 is attached). -Flag 0x08 automatically disables the i586 optimized routines. -.Sh CAVEATS -The emulator is much slower than the NPX coprocessor. -This will result in poor floating-point math performance -if the emulator must be used. -.Pp -The non-GPL emulator does not support the whole set of NPX -instructions. -It is sufficient for booting and configuring a system, but it cannot -support a system with normal workload unless care is taken to compile -the whole system (including third-party packages) with compiler -options that avoid the use of the non-emulated instructions. .Sh BUGS There are lots of them, especially on old cheap motherboards. In particular, some motherboards do not have the interrupt lines from the NPX to the CPU wired properly. -If this is the case, the emulator must be used if consistent system -operation is desired. -.Pp -When using the default -.Dv MATH_EMULATE -option, -transcendental function instructions are not implemented. -Emulation of other instructions is suspect. |