diff options
| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2015-04-12 16:38:39 +0200 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2015-04-12 16:38:39 +0200 |
| commit | 98a7eae9c0cdb31a48c79b34c5f263916a8c1390 (patch) | |
| tree | c017709fd30c0c3f24fa35898d7ae98cd078a3cc | |
| parent | d9880518f0d6923561252e290417c0cd2acd26b5 (diff) | |
segment(3): document fixed segment creation
| -rw-r--r-- | sys/man/3/segment | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/sys/man/3/segment b/sys/man/3/segment index 1a8e5e71e..1564ee0b9 100644 --- a/sys/man/3/segment +++ b/sys/man/3/segment @@ -56,7 +56,7 @@ retrieves and sets the segment's properties. There is only one control message, which sets the segment's virtual address and length in bytes: .EX - va \fIaddress length\fP + va \fIaddress length type\fP .EE .I Address is automatically rounded down to a page boundary and @@ -64,6 +64,12 @@ is automatically rounded down to a page boundary and is rounded up to end the segment at a page boundary. The segment will reside at the same virtual address in all processes sharing it. +Optionally, +.I type +can be specified as +.B fixed +to create a physically continuous segment with a fixed +physical base address suitable for hardware DMA access. When the segment is attached using .IR segattach, @@ -75,7 +81,9 @@ Once the address and length are set, they cannot be reset. .PP Reading the control file returns a message of the same format with the segment's actual -start address and length. +start address and length. For +.B fixed +segments, the type and physical base address are appended. .PP Opening .B data |