.\" svrctl.2 .\" .\" Created: July, 1994 by Philip Homburg .TH svrctl 2 .SH NAME svrctl \- special server control functions .SH SYNOPSIS .nf .ft B #include int svrctl(u32_t \fIrequest\fP, void *\fIdata\fP); .ft R .fi .SH DESCRIPTION .B Svrctl allows root to control the kernel in various ways, or implements some very MINIX 3 specific system calls that don't deserve their own system call number. .PP This system call makes it easy to add new ways of setting and getting kernel parameters, but at the same time, backwards compatibility is not guaranteed. Read the include file to see what the struct's mentioned below look like. Most calls are root-only, unless specified otherwise. .PP The only way to know how to properly use these calls is to study the associated kernel or server code, or the programs that already use these calls. .PP Current requests are: .TP 5 .B MMSIGNON Inform MM that the current process wants to become a server. .TP .B MMSWAPON Instruct MM to mount a file or device as swapspace. .TP .B MMSWAPOFF Tell MM to stop using swapspace. .TP .B FSSIGNON Register a new device with FS. .ig .TP .B FSDEVMAP Translate a device number to a task number, minor device pair using a \fBstruct fsdevmap\fP .. .TP .B SYSSIGNON Inform the kernel that the process want to become a server. The processes task number is filled-in in a \fBstruct systaskinfo\fP. .TP .B SYSGETENV Request the value of one or all boot parameters. Can be used by non-root. .SH "RETURN VALUES" .B Svrctl returns 0 upon success and -1 upon failure. .SH AUTHOR Philip Homburg