Update BfToFloppy and loader code

Author: qwercik

BfToFloppy/src/FloppyImage.cpp

@@ -14,8 +14,8 @@ namespace btf
 	{
 		imageFileContent.assign(FLOPPY_SIZE, 0);
 
-		writeLoader(loaderFilename);
-		int codeSize = assignCode(codeFilename);
+		int loaderSize = writeLoader(loaderFilename);
+		int codeSize = assignCode(codeFilename, loaderSize);
 		replaceFlagWithMachineCode(codeSize);
 	}
 
@@ -29,20 +29,20 @@ namespace btf
 		std::copy(imageFileContent.begin(), imageFileContent.end(), std::ostreambuf_iterator<char>(imageFile));
 	}
 
-	void FloppyImage::writeLoader(const std::string& loaderFilename)
+	int FloppyImage::writeLoader(const std::string& loaderFilename)
 	{
 		std::ifstream loaderFile(loaderFilename, std::ios::binary);
 
 		if (!loaderFile.is_open())
 			throw Error("Couldn\'t find MBR file: " + loaderFilename);
 
 		std::vector<char> loader((std::istreambuf_iterator<char>(loaderFile)), std::istreambuf_iterator<char>());
-		
-		imageFileContent.erase(imageFileContent.begin(), imageFileContent.begin() + loader.size());
-		imageFileContent.insert(imageFileContent.begin(), loader.begin(), loader.end());
+		std::copy(loader.begin(), loader.end(), imageFileContent.begin());
+
+		return loader.size();
 	}
 
-	int FloppyImage::assignCode(const std::string& codeFilename)
+	int FloppyImage::assignCode(const std::string& codeFilename, int offset)
 	{
 		std::ifstream codeFile(codeFilename);
 
@@ -58,8 +58,7 @@ namespace btf
 		if (code.size() > 65536)
 			throw Error("Accteptable brainfuck source code size is 64KiB");
 
-		imageFileContent.erase(imageFileContent.begin() + 512, imageFileContent.begin() + 512 + code.size());
-		imageFileContent.insert(imageFileContent.begin() + 512, code.begin(), code.end());
+		std::copy(code.begin(), code.end(), imageFileContent.begin() + offset); 
 
 		return code.size();
 	}
@@ -82,7 +81,6 @@ namespace btf
 
 		std::vector<uint8_t> opcode = {0xB0, static_cast<uint8_t>(sectorsAmount & 0xFF), 0x90, 0x90};
 
-		imageFileContent.erase(iterator, iterator + 4);
-		imageFileContent.insert(iterator, opcode.begin(), opcode.end());
+		std::copy(opcode.begin(), opcode.end(), iterator);
 	}
 }

BfToFloppy/src/FloppyImage.hpp

@@ -14,8 +14,8 @@ namespace btf
 		void writeToFile(const std::string& floppyImageFilename);
 
 	private:
-		void writeLoader(const std::string& loaderFilename);
-		int assignCode(const std::string& codeFilename);
+		int writeLoader(const std::string& loaderFilename);
+		int assignCode(const std::string& codeFilename, int offset);
 		void replaceFlagWithMachineCode(int brainfuckCodeSize);
 
 		std::vector<uint8_t> imageFileContent;

loader/src/bf.asm

@@ -4,17 +4,6 @@
 DATA_ARRAY_SIZE equ 30000
 
 bf_interpreter:
-	; Set up data for memset
-	mov ax, 0x2000
-	mov es, ax
-	xor di, di
-	
-	xor ax, ax
-	mov cx, DATA_ARRAY_SIZE
-
-	; Something like memset(0x20000, 0, DATA_ARRAY_SIZE)
-	rep stosb
-
 	; Set up segment for brainfuck code
 	mov ax, 0x07E0
 	mov ds, ax
@@ -28,6 +17,13 @@ bf_interpreter:
 							
 	; Set up brainfuck array pointer
 	xor di, di
+	
+	; Set up data for memset
+	xor ax, ax
+	mov cx, DATA_ARRAY_SIZE
+
+	; Something like memset(0x20000, DATA_ARRAY_SIZE, 0)
+	rep stosb
 
 	; Set up brainfuck loops counter
 	xor cx, cx

loader/src/screen.asm

@@ -16,7 +16,7 @@ print_char:
 	cmp al, 0xA
 	jne .end
 	mov al, 0xD
-	call print_char
+	jmp print_char
 
 	.end:
 		ret