small CBDOS tweaks

src/dos_m65/dev_sdcard/dev_sd_cmd_read.s

@@ -18,6 +18,8 @@ dev_sd_cmd_READ:
 
 dev_sd_cmd_READ_dir_blocksfree:
 
+	; Set pointer to '0 BLOCKS FREE.' line
+
 	lda #$13
 	sta SD_ACPTR_LEN+0
 	lda #$00
@@ -28,5 +30,10 @@ dev_sd_cmd_READ_dir_blocksfree:
 	lda #>dir_end
 	sta SD_ACPTR_PTR+1
 
+	; Mark end of directory
+
+	lda #$FF
+	sta SD_DIR_PHASE
+
 	clc
 	rts