diff options
Diffstat (limited to 'share/man')
| -rw-r--r-- | share/man/mmio.9 | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/share/man/mmio.9 b/share/man/mmio.9 new file mode 100644 index 0000000..d960c8c --- /dev/null +++ b/share/man/mmio.9 @@ -0,0 +1,60 @@ +.\" Copyright (c) 2023 Ian Marco Moffett and the VegaOS team. +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions are met: +.\" +.\" 1. Redistributions of source code must retain the above copyright notice, +.\" this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of VegaOS nor the names of its +.\" contributors may be used to endorse or promote products derived from +.\" this software without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +.\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +.\" POSSIBILITY OF SUCH DAMAGE. +.Dd October 4, 2023 +.Dt MMIO 9 +.Os +.Sh NAME +.Nm mmio - vega MMIO interface +.Sh SYNOPSIS +.In sys/mmio.h + +.Bd -literal +static inline void mmio_write8(void *addr, uint8_t val); +static inline void mmio_write16(void *addr, uint16_t val); +static inline void mmio_write32(void *addr, uint32_t val); +#if __SIZEOF_SIZE_T__ == 8 +static inline void mmio_write64(void *addr, uint64_t val); +#endif +__extension__ +.Ed + +.Sh DESCRIPTION +In short, MMIO is a method of writing to registers +of an I/O device via a mapped porition of memory. MMIO +should NOT be done on your own when doing Vega kernel programming. +Instead, rely on Vega's MMIO interface and use +.Ft mmio_read<n>() +and +.Ft mmio_write<n>() +functions. Where `n` is 8 to 32 on 32-bit machines, and to 64 +on 64-bit machines. + +The +.Ft addr +argument can be either a physical address or virtual +address; however, it is recommended to use virtual addresses +for the sake of consistency. |