2010年10月3日 · Memory-mapped IO means that the device registers are mapped into the machine's memory space - when those memory regions are read or written by the CPU, it's reading from or writing to the device, rather than real memory.

2015年4月1日 · The whole point of MMIO is the "MM" part of it - i.e. it's accessible in the normal virtual address space (not some special I/O space), can be remapped by the MMU, etc. – Notlikethat Commented Apr 1, 2015 at 22:00

2023年4月2日 · The MMIO controller uses the memory map to determine the corresponding IO address for the physical address and generates the appropriate IO signals to communicate with the IO device. So, in summary, the mapping between MMIO addresses and IO addresses is maintained by the MMIO controller in the chipset, and this mapping is programmed by the …

2020年2月4日 · MMIO is another solution that has proven popular for simplifying hardware designs. On a typical CPU the core(s) will all be connected to a common bus that allows the cores to read/write to main memory and perhaps shared caches.

2022年10月28日 · I would like to understand how the MMIO works on ARM architecture. I realized that ARM provides 1:1 mapping from physical address to specific peripheral. For example, to manage the GPIOX on arm, for example in Raspberry Pi, the processor accesses the specific physical addresses (seems that preconfigured by the manufacturer?) without configuring ...

2018年9月2日 · The base address of the MMIO area for the configuration space of each PCIe devices in a PCI segment group is given in the ACPI table MCFG. The MCFG table lists, for each PCI segment group, the first and last (inclusive) bus number of the PCI segment group and the base address of the extended configuration space.

2021年7月3日 · IO space (in / out) is a separate address-space from physical memory, including in modern PCI / PCIe devices.It depends on the device how you need to talk to it; modern devices usually only (or mostly) have MMIO registers (in physical address space), because MMIO is more efficient than port IO.

2022年11月2日 · My goal is to memory map the PL of the ZynqMP SoC from the guest VM running on the host using virtio-mmio. The PL base address can by mapped from the host at the physical address 0xA0000000. Doing devmem at 0xA0000000 on the host results in the expected value of 0x00000100:

2012年3月11日 · What I know is that a part of the physical memory is reserved to communicate with the hardware and there's a MMIO Unit involved in taking care of the bus communication and other memory-related stuff. How would a driver communicate with underlying hardware? What are the functions that the driver would use?

2019年7月30日 · mmio A transaction relating to a specific address is received by the Cbo is put through the I/O and DRAM decoder, stored in TOR but not sent to the LLC slice if the IDI opcode is uncacheable (e.g. PRd) which the core sends depending on memory type in PAT/MTRR read on L1 access, except for WCiL, which invalidates aliases in other cores and ...