Modify: bf: add file optional argument

src/kernel/initrd.c

@@ -102,3 +102,33 @@ void cat_initrd(uint8_t* initrd, const char* filename)
 
 	printf("File '%s' not found\n", filename);
 }
+
+int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer)
+{
+	uint8_t* current_block = initrd;
+
+	while (1)
+	{
+		if (current_block[0] == '\0')
+		{
+			//puts("[tar] EOF\n");
+			return -1;
+		}
+
+		const char* file_name = (const char*)current_block;
+		uint32_t file_size = tar_parse_size((const char*)(current_block+124));
+
+		if (strcmp(file_name, filename) == 0)
+		{
+			uint8_t* file_data = current_block + TAR_BLOCK_SIZE;
+			memcpy(buffer, file_data, file_size);
+			buffer[file_size] = '\0';
+			return 0;
+		}
+
+		uint32_t total_size = ((file_size + TAR_BLOCK_SIZE - 1) / TAR_BLOCK_SIZE) * TAR_BLOCK_SIZE;
+		current_block += TAR_BLOCK_SIZE + total_size;
+	}
+	printf("[tar] file '%s' not found\n", filename);
+	return -1;
+}

src/kernel/initrd.h

@@ -33,5 +33,6 @@ typedef struct
 void tar_find_file(uint8_t *tar_start, const char* filename);
 void ls_initrd(uint8_t* initrd);
 void cat_initrd(uint8_t* initrd, const char* filename);
+int tar_file_to_buffer(uint8_t* initrd, const char* filename, char* buffer);
 
 #endif

src/kernel/system.c

@@ -34,6 +34,18 @@ void *memmove(void* dest, const void* src, size_t n)
 	return dest;
 }
 
+void *memcpy(void* dest, const void* src, uint32_t n)
+{
+	uint8_t* d = (uint8_t*)dest;
+	const uint8_t* s = (const uint8_t*)src;
+
+	for (uint32_t i=0; i<n; i++)
+	{
+		d[i] = s[i];
+	}
+	return dest;
+}
+
 void panic()
 {
 	for (;;);	

src/kernel/system.h

@@ -13,6 +13,7 @@ typedef int size_t;
 
 void *memset(void *dest, char val, size_t count);
 void *memmove(void* dest, const void* src, size_t n);
+void *memcpy(void* dest, const void* src, uint32_t n);
 
 struct regs
 {