Updated README

Author: brichard19

README.md

@@ -1,109 +1,151 @@
 # BitCrack
 
-A set of tools for brute-forcing Bitcoin private keys. Currently the project requires a CUDA GPU. The main purpose of this project is to contribute to the effort of solving the [Bitcoin puzzle transaction](https://blockchain.info/tx/08389f34c98c606322740c0be6a7125d9860bb8d5cb182c02f98461e5fa6cd15): A transaction with 32 addresses that become increasingly difficult to crack.
+A tool for brute-forcing Bitcoin private keys. The main purpose of this project is to contribute to the effort of solving the [Bitcoin puzzle transaction](https://blockchain.info/tx/08389f34c98c606322740c0be6a7125d9860bb8d5cb182c02f98461e5fa6cd15): A transaction with 32 addresses that become increasingly difficult to crack.
 
-Currently this project is CUDA only, but I would love to bring it to other architectures if there is enough interest in the project.
 
-## Build dependencies
+### Using BitCrack
 
-Visual Studio 2017
+#### Usage
 
-CUDA Toolkit 9.2
+Use `cuBitCrack.exe` for CUDA devices and `clBitCrack.exe` for OpenCL devices.
 
+Note for OpenCL builds: the .cl files must be in the same directory as clBitCrack.exe, as these are compiled on the fly.
 
-## Using the tools
-
-### Usage
 ```
-BitCrack.exe [OPTIONS] [TARGETS]
+xxBitCrack.exe [OPTIONS] [TARGETS]
 
 Where [TARGETS] are one or more Bitcoin address
 
 Options:
 
 -i, --in FILE
-    Read addresses from FILE, one address per line. If FILE is "-" then stdin is read.
+    Read addresses from FILE, one address per line. If FILE is "-" then stdin is read
 
 -o, --out FILE
-    Append private keys to FILE, one per line.
+    Append private keys to FILE, one per line
 
 -d, --device N
-    Use device with ID equal to N. Run CudaInfo.exe to see a list of available devices.
+    Use device with ID equal to N
 
 -b, --blocks BLOCKS
-    The number of CUDA blocks.
+    The number of CUDA blocks
 
 -t, --threads THREADS
-    Threads per block.
+    Threads per block
 
 -p, --per-thread NUMBER
-    Each thread will process NUMBER keys at a time.
+    Each thread will process NUMBER keys at a time
 
 -s, --start KEY
-    Start the search at KEY. KEY is any valid private key in hexadecimal format.
+    Start the search at KEY. KEY is any valid private key in hexadecimal format
 
 -r, --range RANGE
-    Number of keys to search.
+    Number of keys to search
 
 -c, --compressed
-    Search for compressed keys (default). Can be used with -u to also search uncompressed keys.
+    Search for compressed keys (default). Can be used with -u to also search uncompressed keys
 
 -u, --uncompressed
-    Search for uncompressed keys. Can be used with -c to search compressed keys.
+    Search for uncompressed keys, can be used with -c to search compressed keys
 
+--list-devices
+    List available devices
 
 
 ```
 
-### Examples
+#### Examples
 
 
 The simplest usage, the keyspace will begin at 0, and the CUDA parameters will be chosen automatically
 ```
-BitCrack.exe 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
+xxBitCrack.exe 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
 ```
 
 Multiple keys can be searched at once with minimal impact to performance. Provide the keys on the command line, or in a file with one address per line
 ```
-BitCrack.exe 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH 15JhYXn6Mx3oF4Y7PcTAv2wVVAuCFFQNiP 19EEC52krRUK1RkUAEZmQdjTyHT7Gp1TYT
+xxBitCrack.exe 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH 15JhYXn6Mx3oF4Y7PcTAv2wVVAuCFFQNiP 19EEC52krRUK1RkUAEZmQdjTyHT7Gp1TYT
 ```
 
 To start the search at a specific private key, use the `-s` option:
 
 ```
-BitCrack.exe -s 6BBF8CCF80F8E184D1D300EF2CE45F7260E56766519C977831678F0000000000 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
+xxBitCrack.exe -s 6BBF8CCF80F8E184D1D300EF2CE45F7260E56766519C977831678F0000000000 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
 ```
 
 
 Use the `-b,` `-t` and `-p` options to specify the number of blocks, threads per block, and keys per thread.
 ```
-BitCrack.exe -b 32 -t 256 -p 16 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
+xxBitCrack.exe -b 32 -t 256 -p 16 1FshYsUh3mqgsG29XpZ23eLjWV8Ur3VwH
 ```
 
 Use the `-r` or `--range` option to specify how many keys to search before stopping. For instance, to search up to 1 billion keys from the starting key:
 
 ```
-BitCrack.exe -s 6BBF8CCF80F8E184D1D300EF2CE45F7260E56766519C977831678F0000000000 -r 1000000000
+xxBitCrack.exe -s 6BBF8CCF80F8E184D1D300EF2CE45F7260E56766519C977831678F0000000000 -r 1000000000
 ```
 
 Note:
 
 Integer values can be specified in decimal (e.g. `123`) or in hexadecimal using the `0x` prefix or `h` suffix (e.g. `0x1234` or `1234h`)
 
 
-## Choosing the right CUDA parameters
+### Choosing the right parameters for your device
+
+GPUs have many cores. Work for the cores is divided into blocks. Each block contains threads.
 
 There are 3 parameters that affect performance: blocks, threads per block, and keys per thread.
 
 
-`blocks:` Should be a multiple of the number of compute units on the device. The default is 16 times the number of compute units.
+`blocks:` Should be a multiple of the number of compute units on the device. The default is 32.
 
 `threads:` The number of threads in a block. This must be a multiple of 32. The default is 256.
 
-`Keys per thread:` The performance (keys per second) increases asymptotically with this value. The default is 16. Increasing this value will cause the kernel to run longer, but more keys will be processed.
+`Keys per thread:` The number of keys each thread will process. The performance (keys per second)
+increases asymptotically with this value. The default is 32. Increasing this value will cause the
+kernel to run longer, but more keys will be processed.
+
+
+### Build dependencies
+
+Visual Studio 2017 (if on Windows)
+
+For CUDA: CUDA Toolkit 9.2
+
+For OpenCL: An OpenCL SDK
+
+
+### Building in Windows
+
+Open the Visual Studio solution.
+
+Build the `clKeyFinder` project for an OpenCL build.
+
+Build the `cuKeyFinder` project for a CUDA build.
 
+Note: By default the NVIDIA OpenCL headers are used. You can set the header and library path for
+OpenCL in the `BitCrack.props` property sheet.
+
+### Building in Linux
+
+Using `make`:
+
+Build CUDA:
+```
+make BUILD_CUDA=1
+```
+
+Build OpenCL:
+```
+make BUILD_OPENCL=1
+```
+
+Or build both:
+```
+make BUILD_CUDA=1 BUILD_OPENCL=1
+```
 
-## Supporting this project
+### Supporting this project
 
 If you find this project useful and would like to support it, consider making a donation. Your support is greatly appreciated!