[Solved] EECS3221-MiniProj3_MMU

This project consists of writing a program that translates logical to physical addresses for a virtual address space ofsize 2¹⁶ = 65,536 bytes. Your program will read from a file containing logical addresses and, using a TLB and a pagetable, will translate each logical address to its corresponding physical address and output the value of the byte storedat the translated physical address. Your learning goal is to use simulation to understand the steps involved in translatinglogical to physical addresses. This will include resolving page faults using demand paging, managing a TLB, andimplementing a page-replacement algorithm.

### DetailsYour program will read a file containing several 32-bit integer numbers that represent logical addresses. However,you need only be concerned with 16- bit addresses, so you must mask the rightmost 16 bits of each logical address.These 16 bits are divided into (1) an 8-bit page number and (2) an 8-bit page offset. Hence, the addresses arestructured as shown as:

<!  ><img src=./figs/address.png alt=alt text width=500>

Other specifics include the following:* 2⁸ entries in the page table* Page size of 2⁸ bytes* 16 entries in the TLB* Frame size of 2⁸ bytes* 256 frames* Physical memory of 65,536 bytes (256 frames 256-byte frame size)

Additionally, your program need only be concerned with reading logicaladdresses and translating them to their corresponding physical addresses. You do not need to support writing to thelogical address space.

### Address Translation

Your program will translate logical to physical addresses using a TLB and page table as outlined in Section 9.3. First,the page number is extracted from the logical address, and the TLB is consulted. In the case of a TLB hit, the framenumber is obtained from the TLB. In the case of a TLB miss, the page table must be consulted. In the latter case, eitherthe frame number is obtained from the page table, or a page fault occurs. A visual representation of the address-translationprocess is:

<img src=./figs/vmm.png alt=alt text width=800>

### Handling Page FaultsYour program will implement demand paging as described in Section 10.2. The backing store is represented by the file`BACKING STORE.bin`, a binary file of size 65,536 bytes located in `StartKit` directory. When a page fault occurs, youwill read in a 256-byte page fromthe file BACKING STORE and store it in an available page frame in physical memory. For example, if a logical address withpage number 15 resulted in a page fault, your program would read in page 15 from BACKING STORE (remember that pagesbegin at 0 and are 256 bytes in size) and store it in a page frame in physical memory. Once this frame is stored (andthe page table and TLB are updated), subsequent accesses to page 15 will be resolved by either the TLB or the page table.

You will need to treat BACKING STORE.bin as a random-access file so thatyou can randomly seek to certain positions of the file for reading. We suggest using the standard C library functionsfor performing I/O, including `fopen()`, `fread()`, `fseek()`,and `fclose()`. The size of physical memory is the same as the sizeof the virtual address space, i.e., 65,536 bytes, so you do not need to be concerned about page replacements during a page fault. Later,we describe a modification to this project using a smaller amount of physical memory; at that point, a page-replacementstrategy will be required.

### Test Files Located in StartKitWe provide the file `addresses.txt`, which contains integer values representing logical addresses ranging from 0 to 65535(the size of the virtual address space). Your program will open this file, read each logical address and translate it toits corresponding physical address, and output the value of the signed byte at the physical address.

### How to BeginFirst, write a simple program that extracts the page number and offset based on:

<img src=./figs/address.png alt=alt text width=500>

from the following integer numbers:`1, 256, 32768, 32769, 128, 65534, 33153`

Perhaps the easiest way to do this is by using the operators for bit-masking and bit-shifting. Once you can correctlyestablish the page number and offset from an integer number, you are ready to begin. Initially, we suggest that youbypass the TLB and use only a page table. You can integrate the TLB once your page table is working properly. Remember,address translation can work without a TLB; the TLB just makes it faster. When you are ready to implement the TLB,recall that it has only sixteen entries, so you will need to use a replacement strategy when you update a full TLB.FIFO policy should be used for updating the TLB.

### Page ReplacementThus far, this project has assumed that physical memory is the same size as the virtual address space.In practice however, physical memory is typically much smaller than a virtual address space. This phase of the project nowassumes using a smaller physical address space with 128 page frames rather than 256. This change will require modifyingyour program so that it keeps track of free page frames as well as implementing a page-replacement policy usingLRU (Section 10.4) to resolve page faults when there is no free memory.

### How to Run Your ProgramYou should edit the `test.sh` file to run your program. By doing so, your program will read in the file `addresses.txt`,which contains 1,000 logical addresses ranging from 0 to 65535.Your program is to translate each logical address to a physical address and determine the contents of the signed bytestored at the correct physical address. (Recall that in the C language, the char data type occupies a byte of storage,so we suggest using char values.)

Your program is to output a comma-separated values (CSV) file called `output.csv` that hasthree columns:

* Column 1: the logical address being translated (the integer value being read from `addresses.txt`).* Column 2: the corresponding physical address (what your program translates the logical address to).* Column 3: the signed byte value (i.e., the binary value) stored in physical memory at the translated physical address.

We also provide the file `correct.txt`, which contains the correct physical addressvalues for the file `addresses.txt`. You should use this file to determine if your program is correctly translatinglogical to physical addresses.

### StatisticsAfter completion, your program is to report the following statistics in the standard output (i.e., stdout) as well:1. Page-fault rate: the percentage of address references that resulted in page faults.2. TLB hit rate: the percentage of address references that were resolved in the TLB.

Since the logical addresses in `addresses.txt` were generated randomly and do not reflect any memory access locality,do not expect to have a high TLB hit rate.

### DeliverablesSubmit a zip file containing all files that are required to build and run the project.This includes the `StartKit`, even if you didnt change anything, the `C` source codes, and your `test.sh` file.Please do not submit object files (*.o) or compiled executables.