LinuxQuestions.org
Help answer threads with 0 replies.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware > Linux - Embedded & Single-board computer
User Name
Password
Linux - Embedded & Single-board computer This forum is for the discussion of Linux on both embedded devices and single-board computers (such as the Raspberry Pi, BeagleBoard and PandaBoard). Discussions involving Arduino, plug computers and other micro-controller like devices are also welcome.

Notices


Reply
  Search this Thread
Old 02-18-2022, 07:02 AM   #1
curious_beast
LQ Newbie
 
Registered: Nov 2020
Posts: 3

Rep: Reputation: Disabled
Reading and writing to the system ram from device driver


I have got 0x96000 memory allocated in system ram for audio data.
To read and write I used ioremap, Which while reading back getting
wrong values.

DO I need to use different api's for mapping such a huge physical memory
and acess them in the driver.
 
Old 02-18-2022, 09:38 AM   #2
smallpond
Senior Member
 
Registered: Feb 2011
Location: Massachusetts, USA
Distribution: Fedora
Posts: 4,118

Rep: Reputation: 1258Reputation: 1258Reputation: 1258Reputation: 1258Reputation: 1258Reputation: 1258Reputation: 1258Reputation: 1258Reputation: 1258
ioremap is used for bus memory - memory on adapters that must be accessed through io instructions like readb or writeb. System RAM doesn't use or need this.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Why size of swap space is 2x of RAM??? Why not 1.5x of RAM or 2.5x of RAM??? Saurav Ghosh Linux - Newbie 7 11-01-2011 04:49 AM
[SOLVED] writing and reading driver value in ioctl Vermidias Linux - Kernel 1 01-19-2011 01:54 AM
Writing/reading to a modem via serial device? R00ts Programming 3 01-06-2011 06:02 PM
reading and writing to configuration register of PCI device giri_blr Linux - Kernel 0 08-14-2008 01:43 AM
reading and writing to a serial device (modem) Xanadu Linux - Laptop and Netbook 0 01-04-2005 11:05 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware > Linux - Embedded & Single-board computer

All times are GMT -5. The time now is 12:15 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration