diff options
| -rw-r--r-- | share/man/man4/man4.i386/npx.4 | 38 |
1 files changed, 27 insertions, 11 deletions
diff --git a/share/man/man4/man4.i386/npx.4 b/share/man/man4/man4.i386/npx.4 index 0fbdafe56e72..e742e7c5c507 100644 --- a/share/man/man4/man4.i386/npx.4 +++ b/share/man/man4/man4.i386/npx.4 @@ -37,9 +37,11 @@ .Nm npx .Nd Numeric Processing Extension coprocessor and emulator .Sh SYNOPSIS +.Cd "device npx0 at nexus? port IO_NPX flags 0x0 irq 13" .Cd "options MATH_EMULATE" +.Cd "options GPL_MATH_EMULATE" .\" XXX this is awful hackery to get it to work right... -- cgd -.Cd "device npx0 at isa? port IO_NPX irq 13" +.\" What the heck does he mean? - cracauer .Sh DESCRIPTION The .Nm npx @@ -57,20 +59,34 @@ coprocessors. The 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 "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. +If there is no NPX present in the system, the "MATH_EMULATE" or +"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 +For a description of the possible "flags" values see the LINT kernel +configuration file. .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 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. +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 -Emulation of the transcendental functions instructions is incorrect. +Emulation of the transcendental functions instructions in the non-GPL +emulator is incorrect. Emulation of other instructions is suspect. |