Abstract:
Near Field Communication (NFC) supports server information handling system management through communication between a mobile information handling system and a baseboard management controller. Enhanced transfer by NFC of management information is provided by manipulating the NFC tag memory assigned for information transfer with the aid of a microcontroller coordinating NFC transfers at the baseboard management controller, such as with coordinated storage operations at a tag memory an supporting processors/microcontrollers. The microcontroller manages tag memory and/or system memory so that the portable information handling system writes and reads information beyond the capabilities of unaided tag memory.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    U.S. patent application Ser. No. ______, entitled “NFC Communication with an Information Handling System Supplemented by a Management Controller” by inventors Arulnambi Raju and Sudhir V. Shetty, Attorney Docket No. DC-102679.01, filed on even date herewith, describes exemplary methods and systems and is incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates in general to the field of information handling system wireless communication, and more particularly to near field communication (NFC) with an information handling system supplemented by a management controller. 
         [0004]    2. Description of the Related Art 
         [0005]    As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
         [0006]    Many enterprises have turned to network-based “cloud” infrastructures to manage information processing requirements. A typical cloud infrastructure attempts to balance processing demands and processing resources by allocating processing tasks across generally generic server information handling systems. For example, a typical cloud infrastructure is a farm of server information handling systems that reside in a datacenter with server tasks assigned through migration of virtual machines between physical resources. In such a cloud infrastructure, the actual physical location of a virtual information handling systems is often difficult to track and generally irrelevant. Often, a datacenter will support multiple enterprises in different “virtual” cloud networking environments that run on the same physical server information handling systems. 
         [0007]    One concern that arises with cloud networking is maintaining security for data associated with different entities that share hardware resources. Generally, the cloud infrastructure uses data structures, encryption and password protection to maintain separation of data through network accesses. These techniques also help to restrict access of data when an end user has a physical interface to server information handling systems within a datacenter, such as a datacenter technician. For instance, physical resources within a server information handling system are often managed by a baseboard management controller (BMC) that does not have access to virtual machines running on the server information handling system. Data center technicians interact with the BMC through a management network interface or a direct cable connection. The BMC allows a datacenter technician to monitor the status of physical resources and to configure the physical resources to interact with the cloud infrastructure, such as with network address and other settings. 
         [0008]    Generally, communications with the BMC are kept secure and separate from communications through the cloud. Restricting BMC communications helps to prevent malicious accesses that could reconfigure a server information handling system or cause damage to components within the server information handling system. Typically, management network communications take place though wired interfaces, such as an Ethernet cable that connects to a local area network (LAN). In some instances, BMC communications are supported through wireless communications, such as a wireless local area network (WLAN). Generally, however, security requirements limit the ability to use WLAN communications with a server information handling system and the management network associated with a BMC. Wireless networking in a server information handling system data center creates a security risk in that unauthorized individuals might sniff wireless communications or even hack into the server through the wireless network. 
         [0009]    One alternative to wireless networking in a server information handling system data center to communicate with a BMC is to include a near field communication (NFC) device that interfaces with the BMC. Mobile telephones that include NFC can communicate directly with the BMC through short range wireless signals that present minimal security risk since the NFC wireless signals do not carry to a distance that would extend beyond a typical datacenter secure area. However, NFC has limited bandwidth for communicating information and generally requires placement of the two communicating NFC devices in close proximity to each other. For example, a typical NFC “tag” memory space has only  3 k of flash memory that is reloaded for each transmission or reception of data. As a result, an end user generally has to hold a mobile telephone in close proximity to a server information handling system NFC device for an extended time in order to communicate a meaningful amount of information. 
         [0010]    One difficulty that arises with management of server information handling systems by NFC is that some server management data changes frequently and is thus constantly updated, such as system health and hardware logs. In order to ensure that the most recent data is available from an NFC device, this data would need frequent updates to the tag memory of the NFC device, which tends to wear internal flash memory used for tag memory. Other difficulties include ensuring that an NFC transaction has proper authorization with the BMC and ensuring that content is synchronized between NFC access to a BMC and other types of access, such as through a conventional management network interface Although NFC transactions might be arranged to provide the same access to management information at a BMC as is available through conventional management networks, NFC transaction tend to take more time than conventional network communications and sometimes involve holding a portable information handling system in an awkward position within close proximity to an NFC device that can lead to end user discomfort. 
       SUMMARY OF THE INVENTION 
       [0011]    Therefore a need has arisen for a system and method which supplements an NFC communication device with a management controller to increase NFC data transmission efficiency. 
         [0012]    A further need exists for a system and method which manages NFC transactions through virtual tag file locations managed by a server information handling system management subsystem to support reads by an external NFC device. 
         [0013]    In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for communication of data with an NFC communication device. A microcontroller manages NFC transceiver memory for reads and writes that selectively adapt NFC transactions to a virtual tag size. An external NFC device uses selectable tag memory sizes advertised by the microcontroller managed NFC transceiver. Microcontroller memory is partitioned by a server information handling system baseboard management controller (BMC) to provide a virtual tag memory view for NFC reads and writes by the external NFC device. 
         [0014]    More specifically, a server information handling system includes a server management subsystem having a baseboard management controller (BMC) to manage processing components of the server information handling system. An NFC device integrated with the server management subsystem interfaces the BMC with an external NFC device of a portable information handling system, such as a smartphone, so that the portable information handling system performs management functions at the BMC with NFC communication transactions. A microcontroller interfaces the BMC with the integrated NFC device and selectively modifies memory accessed by an NFC transceiver of the integrated NFC device to provide increased NFC transaction sizes and transfer rates. Reading and writing cues provided as configuration information to an external NFC device define a tag memory of greater than the actual tag memory associated with the NFC transceiver. The microcontroller manages memory usage by the NFC transceiver, such as by forwarding writes received by the NFC transceiver to memory external to the tag memory and by providing the NFC transceiver information to respond to read requests from memory external to the tag memory. 
         [0015]    In one embodiment, a BMC defines file locations in a microcontroller memory so that a virtual tag memory maps to physical memory locations in the microcontroller. An external NFC device references the file locations to select and retrieve desired management information with NFC transactions serviced by a server subsystem NFC transceiver controlled by the microcontroller. The BMC defines file locations so that management information that is frequently updated, such as maintenance logs for the server and the server components, are kept in microcontroller RAM while less frequently updated information, such as server identification information, are kept in microcontroller flash memory. In order to maintain concurrency of data in the microcontroller, data is locked during reads for NFC transactions so that writes are not made to files when a read is in progress. Security is ensured by requiring LDAP security, such as user name and password inputs, before NFC transactions that transfer server data are permitted. 
         [0016]    The present invention provides a number of important technical advantages. One example of an important technical advantage is that NFC communications are performed more efficiently with more rapid transfer rates and greater quantities of data transferred in a single NFC communication. A microcontroller manages NFC transfers with support from memory outside the NFC device so that the effective memory of an NFC tag is practically unlimited. By coordinating reads and writes through an address translation, the microcontroller effectively creates a dual ported memory for the NFC tag to support complex and rapid data transfers for server information handling system configuration. Memory locations in the microcontroller are mapped to a virtual tag view by a server BMC so that the BMC and external NFC devices can read and write selected data in efficient NFC transactions. By allocating different types of information to persistent and non-persistent memory, interruptions to the BMC are reduced, such as when static information like IP addresses are requested that does not require BMC inputs. Thus, the BMC is better able to focus resources at management tasks without servicing the NFC transceiver for responses that the microcontroller handles on its own with persistently stored information. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
           [0018]      FIG. 1  depicts a server information handling system having management support through an NFC interface with a portable information handling system; 
           [0019]      FIG. 2  depicts a block diagram of a server management subsystem with NFC interface support; 
           [0020]      FIG. 3  depicts a flow diagram of a process that provides concurrent access of NFC tag memory for information transfers; 
           [0021]      FIG. 4  depicts a flow diagram of a process that provides an NFC interface with support by memory external to tag memory; 
           [0022]      FIG. 5  depicts a flow diagram of a process that provides an NFC interface to receive a write without storage at the tag memory; 
           [0023]      FIG. 6  depicts a flow diagram of a process that provides an NFC interface to send a write without storage at the tag memory; 
           [0024]      FIG. 7  depicts a block diagram of a server management subsystem that translates NFC transfers to memory external to tag memory by reference to a virtual map; 
           [0025]      FIG. 8  depicts a block diagram of an example embodiment of memory mapping at an NFC microcontroller to transfer server management information between a server BMC and an external NFC device; 
           [0026]      FIG. 9  depicts a functional block diagram of NFC transfers with data locked by microcontroller; and 
           [0027]      FIG. 10  depicts a functional block diagram of secure NFC transfers at a server BMC. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    NFC transactions are supported at a server information handling system BMC with microcontroller memory managed by the BMC. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
         [0029]    Referring now to  FIG. 1 , a server information handling system  10  is depicted having management support through an NFC interface with a portable information handling system  12 . In the example embodiment, server information handling system  10  is disposed in a server information handling system rack  14  at a slot  16 . Rack  14  provides power and communication infrastructure to a plurality of slots  16  to support a plurality of server information handling systems  10 . Each server information handling system  10  has a chassis  18  that holds processing components for performing server processing functions, such as a one or more central processing units (CPUs)  20  to execute instructions, random access memory (RAM)  22  to store instructions, hard disk drives (HDD)  24  to provide persistent storage, a chipset  26  having firmware to coordinate operations of the processing components, and one or more network interface cards (NIC)  28  to provide network communications. A baseboard management controller (BMC)  30  manages operation of the processing components with communications supported through a management network interface, sometimes referred to as an out-of-band or management network. BMC  30  allows remote management of server operations, such as remote start-ups, remote shut downs, and remote firmware upgrades or other types of maintenance. 
         [0030]    A near field communication (NFC) device  32  interfaces with BMC  30  to provide server management support through NFC wireless transmissions provided by a portable information handling system  12 . For example, portable information handling system  12  accepts management settings through a touchscreen display  34  that presents an interface generated by an application  36  running on portable information handling system  12 . Application  36  coordinates communication of server management information through an NFC device  32  of portable information handling system  12  to NFC device  32  of server information handling system  10 . Although BMC  30  is capable of performing substantially the same management tasks through NFC transactions as it can perform through a management network supported by a NIC  28 , data transfer rates for conventional NFC transactions tends to take place at a slower pace with NFC transactions. To improve data transfer rates, NFC device  32  in server information handling system  10  adjusts NFC transactions to occur more efficiently both with and without prior coordination of NFC device  32  and application  36  in portable information handling system  10 . As an example, typical NFC transactions are supported in a maximum of 10 KB increments based upon the size of tag memory within each NFC device  32 , however, server management NFC transactions are supported in 100 KB or greater increments by, in essence, spoofing the NFC transceivers to view available tag memory as greater than actual tag memory. Memory can be written in any size memory increments with a spoofing-type of memory rolling pages mechanism in which tag physical memory is looped back on itself and re-used as the microcontroller reads incoming data from tag memory locations. Although, in such an embodiment, tag memory has a limited physical size, the re-use of tag memory allows presentation of a larger virtual memory size to the external NFC device. Larger and more efficient NFC transactions may be coordinated by compatible NFC devices  32  that share transfer toolboxes, or may be induced from one device by providing tag memory configuration information that differs from actual tag memory configuration, as set forth below. 
         [0031]    Referring now to  FIG. 2 , a block diagram depicts a server management subsystem  38  with NFC interface support. BMC  30  controls management functions at server management subsystem  38  and has access to system memory  40 , which can include RAM or flash memory local to BMC  30 , RAM or persistent memory local to the managed server information handling system, or network storage accessed through a network interface. A microcontroller  42  interfaces BMC  30  with NFC device  32  to coordinate management functions performed through NFC transactions. NFC device  32  includes an NFC transceiver  44  with a conventional tag memory  46  and NFC configuration information  48  to support conventional NFC transactions. For example, NFC devices  32  of server information handling system  10  and portable information handling system  12  exchange NFC configuration information  48  and then communicate data in increments indicated by the size of tag memory  46 . 
         [0032]    Microcontroller  42  provides enhanced NFC transaction sizes and transfer rates by selectively altering NFC configuration information  48  to have values different from the values used for access to tag memory  46 . In one embodiment, microcontroller  42  sets a flag to indicate the availability of enhanced NFC transactions to application  36 . If application  36  has logic to employ enhanced NFC transactions, the application  36  coordinates with microcontroller  42  to establish appropriate NFC transaction parameters. However, microcontroller  42  effectively alters the nature of NFC transactions with server-side logic in the event that application  36  lacks inherent capabilities. In a concurrent mode of operations, microcontroller  42  reads and writes information to tag  46  concurrent with NFC transceiver  44  reading and writing information at tag  46  in support of NFC transactions. In the concurrent mode of operations, microcontroller  42  sets tag size in NFC configuration  48  so that an external NFC device  32  reads and writes NFC transactions in excess of the actual size of tag memory  46 . As the NFC transaction takes place at NFC transceiver  44 , microcontroller  42  accesses tag memory  46  to read and/or write information, thus allowing reuse of tag memory  46  during the NFC transaction. Reading and writing cues provided by NFC configuration information  48  include tag memory address information that differs from actual tag memory address information, such as address and size for a tag memory for any range supported by microcontroller  42 , or selectable address ranges supported by microcontroller  42 . Reading and writing cues may be recognized by an external NFC device  32  as an indication of support for altered NFC transactions to adapt the NFC transactions appropriately, or may simply be adopted as the actual tag memory used by the external NFC device. 
         [0033]    In one embodiment, microcontroller  42  manages tag memory  46  accesses for reads and writes by controlling information at buffers  50  that store information between NFC transceiver  44  and tag memory  46 . In a write forwarding mode, tag writes are pushed from tag memory  46  (or directly from buffer  50  before a write to tag memory  46 ) to an address range external to tag memory  46 . For example, microcontroller  42  sets NFC configuration  48  to have a tag memory size in excess of the actual size of tag memory  46 , and then pushes writes to the tag memory  46  directly to memory external tag memory  46  (or to re-used tag memory) that has adequate size for storing the NFC read or write transaction. Write forwarding may send information to RAM or flash memory of microcontroller  42 , to memory associated with BMC  30  or even to network memory external to server information handling system  10 . Similarly, microcontroller  42  coordinates a remote read mode so that NFC writes from NFC transceiver  44  are supported by memory external to tag memory  46 . For example, NFC configuration  48  has a larger tag memory size set than is in fact available from tag memory  46 , however, reads by an external NFC device  32  are supported by feeding information for the read from microcontroller  42  instead of or in addition to from tag memory  46 . In combination, write forwarding and remote reads as set forth above allow an NFC device to have essentially an infinite virtual tag memory size. To track NFC transactions, microcontroller  42  maintains a virtual to physical address space to remap blocks of physical tag memory to a virtual address space. By continually updating the map with read and write cues, microcontroller  42  defines an infinite tag memory that relies on reuse of tag memory blocks or use of memory external to tag memory  46 . 
         [0034]    In one embodiment, a tag memory presents an infinite or very larger virtual tag memory size to an external device and maintains data during NFC transactions by looping the tag memory page over itself. For example, a 10 byte tag memory presents itself as having an unlimited or very large size, such as 1 MB. An external NFC device interfacing with the tag memory uses tag memory with reads/writes through the physically-available 10 bytes of memory. At the 11 th  byte, tag memory loops back to the first memory byte location, with data previously written to that location already moved to memory outside the tag memory. The external NFC device reads/writes at the first byte through the 10 th  byte while viewing the tag memory as and 11 th  through 20 th  byte. The tag memory continues to loop its memory locations to provide a memory size needed by the external NFC device to complete a read/write transaction. The microcontroller manages virtual tag memory size by mapping the physical memory address of the looped tag memory to a location external to the tag memory. Alternatively, in one embodiment, tag memory itself automatically implements looping by reading and writing to buffers as writes/reads take place to the tag memory. Reads and writes to tag memory are managed to ensure that data in a tag memory location is read or written by an NFC transaction before the memory location is re-used by a looping operation. For example, in one embodiment an interrupt service routine (ISR) mechanism manages tag memory location re-use. As soon as a defined amount data, such as a defined data block, is modified by an external NFC device, the tag memory notifies an external microcontroller of the availability of the memory block. The microcontroller then asserts a GPIO to let the tag memory know that the microcontroller is reading or writing, with the GPIO asserted while the microcontroller is active to ensure the tag will not overwrite memory blocks in a looping operation. In an alternative embodiment, a lock register is used for the tag memory to check before accessing and overwriting existing data in a data block. Similar mechanisms may be used when a BMC or a microcontroller is trying to access data that is being modified by an external NFC device. 
         [0035]    Referring now to  FIG. 3 , a flow diagram depicts a process that provides concurrent access of NFC tag memory for information transfers. The process starts at step  52  by sending NFC configuration information to an external NFC device that indicates concurrent access support, such as a flag or a tag memory size greater than the actual tag memory size. At step  54 , a determination is made of whether a read or write transaction is requested that calls for concurrent access. If an external NFC device requests a read transaction, the process continues to step  56  to send read information from the microcontroller to the tag memory for communication of the read information to the external NFC device by the NFC transceiver at step  58 . At step  60 , concurrent with communication of the read information by the NFC transceiver from the tag memory, the microcontroller re-populates portions of the tag memory with additional read information so that the transceiver may continue rolling through tag memory repeatedly until the NFC read transaction is complete. At step  62 , when the read transaction completes, the next transaction is made available. 
         [0036]    If at step  54  a write NFC transaction is indicated, the process continues to step  64  to send the write information form the external NFC device through the NFC transceiver to the tag memory. At step  66 , the write information stored in the tag memory is sent from the tag memory to the microcontroller as it is received by the NFC transceiver, thus freeing tag memory to accept additional write information. At step  68 , concurrent with writes of information to the tag memory by the NFC transceiver, the microcontroller resets tag memory where information was transferred to the microcontroller so that the external NFC device can write to locations in the tag memory that have already been used in the NFC transaction. Thus, an external NFC device writes to the NFC transceiver based upon a tag memory size that is greater than the actual tag memory size and the microcontroller manages tag memory to reuse memory blocks during the write transaction. The result of concurrent writes and reads from a tag memory by both an NFC transceiver and microcontroller is a transition of tag memory into dual ported memory that allows for rolling NFC transactions cumulatively greater than available tag memory. 
         [0037]    Referring now to  FIG. 4 , a flow diagram depicts a process that provides an NFC interface with support by memory external to tag memory. At step  70 , an NFC transaction is detected at an NFC transceiver so that read and write cues are enabled to effectively transition tag memory transactions to support sizes and rates unavailable with the use of just tag memory. Cues are also available to let other entities know that a read/write is being performed. For example, a cue notifies the microcontroller to read data so the microcontroller reads trail in a loop behind external NFC device writes. In the example embodiment of an external NFC device reading from a tag memory, the microcontroller can lead by writing new information in the memory while the external NFC device reads the tag memory in a trailing loop operation. At step  72 , the NFC transceiver alerts the microcontroller of the pending NFC transaction. At step  74 , microcontroller memory is associated with the NFC transaction to support transactions of greater than that available with tag memory. At step  76 , the microcontroller memory for the NFC transaction is provided to the NFC transceiver for communication to the external NFC device, such as in the form of NFC configuration information. Microcontroller memory may be provided as a size of greater than the actual tag memory size, an addressed size to an address external to the tag memory, or by selectable address ranges. At step  78 , the microcontroller memory is used to support the NFC transaction in the place of the tag memory so that the tag memory is not used in the NFC transaction. In alternative embodiments, tag memory may be used, such as in a rolling store that is reused as described above or as part of the addressed memory provided by the microcontroller. 
         [0038]    Referring now to  FIG. 5 , a flow diagram depicts a process that provides an NFC interface to receive a write without storage at the tag memory. In this write forwarding mode, when a tag is received at an NFC transceiver, the transceiver pushes the write address and data to a microcontroller selectable address range that provides memory beyond that available from the tag memory. At step  80 , a tag write is received at the NFC transceiver. In one embodiment, the sending NFC device sends a tag that is greater than the tag memory of the receiving NFC device based upon a tag configuration provided by a microcontroller of the receive NFC device. The microcontroller manages information received by the NFC transceiver of the receiving NFC device to support NFC transactions of greater than the tag memory size. At step  82 , the tag write is pushed from the NFC transceiver to the microcontroller so that the NFC transaction can accept a write of information greater than available tag memory space. The write forwarding may roll through tag memory so that tag memory is reused during the write or may proceed from the NFC transceiver buffer directly to the microcontroller. As step  84 , the tag write is stored in the microcontroller memory or other memory accessible by the microcontroller. 
         [0039]    Referring now to  FIG. 6 , a flow diagram depicts a process that provides an NFC interface to write information from a first NFC device to a second NFC device in response to a read request from the second NFC device without storage of the information at the tag memory. At step  86 , a microcontroller memory location is provided as NFC configuration information from the first NFC device to the second NFC device, such as identified as the tag memory. The microcontroller memory location may be, for instance, a memory address and size or a range of addresses and sizes located in the microcontroller. At step  88 , a read request by the second NFC device is serviced by requesting information by the NFC transceiver of the first NFC device from the microcontroller based upon the NFC configuration memory location. At step  90 , information is written forward from the microcontroller memory to the NFC transceiver for communication to the second NFC device in response to the read request. In one embodiment, the microcontroller writes to the NFC transceiver buffer so that tag memory is not used for the forwarding of the information. 
         [0040]    Referring now to  FIG. 7 , a block diagram depicts a server management subsystem  38  that translates NFC transfers to memory external to tag memory  46  by reference to a virtual map  94 . Microcontroller  42  includes a virtual map manager  92  to remap blocks of physical tag memory  46  to a virtual address space tracked in virtual map  94 . Virtual map manager  92  continually remaps blocks in cooperation with the read and write cues as set forth above to effectively create an infinitely sized tag. An address translator  96  operating in cooperation with NFC transceiver  44  ensures that information written from and read to NFC transceiver  44  based upon address locations of tag memory  46  comes from and is sent to the appropriate virtual locations. 
         [0041]    Referring now to  FIG. 8 , a block diagram depicts an example embodiment of memory mapping at an NFC microcontroller  42  to transfer server management information between a server BMC  30  and an external NFC device. BMC  30  interfaces with microcontroller  42  through a management link  98 , such as an I2C link. BMC  30  obtains a virtual NFC tag memory view in I2C offset  100  that presents files with a virtual storage range and size. BMC  30  writes and reads management information at microcontroller  42  by reference to the virtual NFC tag memory view  100 . Actual memory transactions are mapped from the virtual NFC tag memory view  100  to the microcontroller  42 ′s internal physical memory  102  based upon a memory location definition set by a file location register  104 , which maps each virtual memory files  106  to physical memory files  108 . In the example embodiment, file location register  104  defines whether each virtual memory file maps to physical memory file  108  in non-persistent RAM  110  or in persistent flash memory  112 . BMC  30  defines the file location register  104  values so that desired management information is stored in desired file locations. An external NFC device that has file location register  104  values, obtained ahead of time or with an NFC communication, is able to selectively download only desired files by identify the desired files in an NFC communication. For example, an application running on a mobile phone may include the file location register for a BMC and use the file location register to coordinate a more direct NFC transaction for desired information. Thus, in order to limit the time taken for an NFC transaction, a portable information handling system  12  identifies only the locations that are desired or selects specific files, such as by an address range associated with a file in the file location register, to have less than all available management information communicated in an NFC transaction. 
         [0042]    In one embodiment, BMC  30  defines file locations in file location register  104  so that management information is stored in RAM  110  or flash  112  based upon the frequency of updates made to the management information. For example, basic identification information of server information handling system that changes infrequently, such as IP and MAC addresses and a server component inventory, are stored in flash  112 , while more frequently updated information, such as error and operational logs for the server and health information and sub-system health on the server, are stored in RAM  110 . This arrangement helps to prolong the life of microcontroller  42  and an associated NFC transceiver  44  by reducing wear at flash memory  112 . Essentially, file location register  104  defines a partition between persistent and non-persistent memory so that microcontroller  42  acts as a virtual NFC tag memory with more frequently updated information stored in RAM  110  as the information is updated so that NFC transactions with most recent management information are available as updates are made without burnout of flash memory by repeated writes. 
         [0043]    Referring now to  FIG. 9 , a functional block diagram depicts NFC transfers with data locked by a microcontroller disposed in an NFC device  32 . Locking files during NFC transactions ensures concurrency of management data by preventing writes on data while the data is being transferred in response to a read request. In the example embodiment, the data request is initiated at step  116  from portable information handling system  12  to NFC device  32  disposed within a server management subsystem, however, in alternative embodiments, the data request is initiated from BMC  30 . NFC device  32  at step  118  locks the requested file to prevent writes to the requested file. At step  120 , BMC  30  attempts to write to the requested file, such as with a log update, and at step  122  a write fail is returned to BMC  30 . At step  124 , such as concurrent with the write attempt by BMC  30 , portable information handling system  12  reads the requested file with an NFC transaction and, at step  126  a read success is returned. At step  128 , the requested file is unlocked at the successful read so that, at step  130 , a write request to the file by BMC  30  is accepted. In response to the BMC write request, at step  132  the requested file is locked and at step  134  a write success is returned to BMC  30 . Finally at step  136 , the requested file is unlocked to allow subsequent reads and writes. 
         [0044]    Referring now to  FIG. 10 , a function block diagram depicts secure NFC transfers at a server BMC  30 . At initial setup, a secret value b is stored at portable information handling system  12 , and two public values, p(prime) and g(primitive root mod p), and a secret value a are used at BMC  30  to calculate public value A. At step  138 , BMC  30  writes values p,g and A to NFC device  32 , and at step  140  an NFC transfer provides values p,g and A to portable information handling system  12 . At step  142 , portable information handling system  12  calculates public value B, at step  144 , portable information handling system  12  computes shared secret value s and at step  146 , portable information handling system  12  encrypts credentials C into C′, such as an LDAP user name and password, using value s and configures an XML payload P. In one embodiment, sensitive information is encrypted and payload P is digitally signed. At step  148 , portable information handling system  12  writes an NFC transaction to NFC device  32  with values P,C′ and B. At step  150 , BMC  150  retrieves values P, C′ and B, and applies the values to compute the shared secret value s at step  152 , to decrypt C′ at step  154 , to authenticate C at step  156 , and, if C authenticates, to apply the configuration XML payload P and post results of the payload back to NFC device  32  by a write at step  160 . Once the results are posted, portable information handling system  12  obtains the payload with an NFC transaction. 
         [0045]    Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.