MAN page from RedHat Other pcmcia-cs-3.0.0-1.i386.rpm

MEMORY_CS

Section: Devices and Network Interfaces (4)
Updated: 1997/09/05 04:51:15
Index

NAME

memory_cs - MTD-aware PCMCIA memory card driver

SYNOPSIS

insmod memory_cs.o[pc_debug=n][mem_speed=n][word_width=n]

DESCRIPTION

Memory_csis the Card Services driver for PCMCIA memory cards, and also providesdirect memory access for other types of cards.It provides character-mode and block-mode for accessing any card'sattribute and common memory address spaces, analogous to/dev/mem.Memory_cswill allocate a free major device number when it is loaded. Itprovides two types of minor devices: "direct" character-mode devicesfor raw access a card's entire PCMCIA common and attribute memoryspaces, and "indirect" devices for accessing specific memorypartitions via an appropriate Memory Technology Driver. Thebitwise layout of minor device numbers is 'ddddxarr'. 'dddd'is the device number, with one card counting as one memory device.memory, and 'rr' is the region number (for indirect devices). Whenmemory_csis bound to a card, it will report its major and minor device numberstocardmgr(8).

The default memory card initialization script creates characterspecial device files for the direct common memory and attribute memorydevices. It also creates character special devices for accessing thefirst attribute and common memory partitions, and a block device foraccessing the first common memory partition. These devices have thefollowing names:

/dev/mem#c: Common memory direct access, character special device.
/dev/mem#a: Attribute memory direct access, character special device.
/dev/mem#c0c: Common memory region 0, character special device.
/dev/mem#c0b: Common memory region 0, block special device.
/dev/mem#a0c: Attribute memory region 0, character special device.

The block special device for a card's common memory can be used tocreate a filesystem on a card, and the device can be mounted in muchthe same way as a floppy disk. In some cases, you may need toexplicitly specify the card's capacity when creating a filesystem.

The character special devices can be used to read and write arbitrarynumbers of bytes to arbitrary locations. For devices that need to beexplicitly erased before writing, if a write request is aligned andsized on erase block boundaries for the target memory card, the driverwill erase the target region before writing to the card.

Since any PCMCIA card can be accessed as a memory card,memory_cscan be bound to any card regardless of function, and regardless ofwhat other drivers might also be bound to that card. For example,this driver can be bound to a card and then used to read out thecontents of the card's attribute memory.

PARAMETERS

pc_debug=n: Selects the PCMCIA debugging level. This parameter is only availableif the module is compiled with debugging enabled. A non-zero valueenables debugging.
mem_speed=n: Sets the access speed of the shared memory window for direct accessdevices, in nanoseconds. The default is 0 (i.e., no extra waitstates). Values of up to 1000 are legal.
word_width=n: A flag indicating if direct access devices should be configured for8-bit (if 0) or 16-bit (if 1) transfers. The default is 1 (16-bit).

AUTHOR

David Hinds - dhindsAATThyper.stanford.edu

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