Add fs_read and fs_write functions and some testing

2 files changed, 28 insertions, 7 deletions

diff --git a/src/filesystem.c b/src/filesystem.c
index 2da77be..1521d69 100644
--- a/src/filesystem.c
+++ b/src/filesystem.c
@@ -116,3 +116,18 @@ fs_write(u8 *src, size_t n_bytes, u16 file_index, u16 offset, bool append) {
 
     return n_bytes;
 }
+
+int
+fs_read(u8 *dst, size_t n_bytes, u16 file_index, u16 offset) {
+    File *file = &filesystem.files[file_index];
+
+    // Check if the offset is within limits.
+    if (offset + n_bytes >= FILE_MAX_SIZE) {
+        return -1;
+    }
+
+    // Copy n_bytes to destination.
+    _fs_read(dst, FILE_DATA_OFFSET + FILE_MAX_SIZE * file_index + offset, n_bytes);
+
+    return n_bytes;
+}
diff --git a/src/main.c b/src/main.c
index 798dc18..79bf788 100644
--- a/src/main.c
+++ b/src/main.c
@@ -271,20 +271,26 @@ int main(void) {
 
     // DEBUG:...
     int file_idx;
+    char tmp_buffer[KB(1)] = {0};
     if ((file_idx = fs_open_file("HELLO_FILE")) >= 0) {
         fs_write("HEY", 3, file_idx, 0, false);
         fs_write("THERE", 3, file_idx, 1, true);
-        txt_printf("nam: %s\n", filesystem.files[file_idx].name);
-        txt_printf("num: %d\n", filesystem.num_files);
-        txt_printf("size: %d\n", filesystem.files[file_idx].size);
+        txt_printf("file name: %s\n", filesystem.files[file_idx].name);
+        txt_printf("file size: %d\n", filesystem.files[file_idx].size);
+        if (fs_read(&tmp_buffer, filesystem.files[file_idx].size, file_idx, 0) > 0) {
+            txt_printf("READ: %s\n", tmp_buffer);
+        }
     }
     if ((file_idx = fs_open_file("HELLO_FOLKS")) >= 0) {
-        fs_write("BY GOD", 6, file_idx, 0, false);
+        fs_write("AAAAAA", 6, file_idx, 0, false);
         fs_write("XXX", 3, file_idx, 1, true);
-        txt_printf("nam: %s\n", filesystem.files[file_idx].name);
-        txt_printf("num: %d\n", filesystem.num_files);
-        txt_printf("size: %d\n", filesystem.files[file_idx].size);
+        txt_printf("file name: %s\n", filesystem.files[file_idx].name);
+        txt_printf("file size: %d\n", filesystem.files[file_idx].size);
+        if (fs_read(&tmp_buffer, filesystem.files[file_idx].size - 1, file_idx, 1) > 0) {
+            txt_printf("READ: %s\n", tmp_buffer);
+        }
     }
+    txt_printf("num files: %d\n", filesystem.num_files);
 
     // Main loop.
     int frame_counter = 0;