[breaking change] 70 shared resources cc65 api

include/mega65/fileio.h

@@ -82,7 +82,7 @@ chdir(char* filename);
 __attribute__((leaf))
 #endif
 uint8_t
-chdirroot(void);
+chdirroot(uint8_t partition);
 
 /**
  * @brief Struct for holding version information of the hypervisor

src/cc65/fileio.s

@@ -146,10 +146,15 @@ _close:
 	rts
 
 _chdirroot:
+	;; HYPPO requires partition number in X.
+	tax
 	;; Change to root directory of volume
 	lda #$3C
 	sta $d640
 	clv
+	;; HYPPO trap_dos_cdroot() doesn't set return value: It is deemed to always succeed
+	;; if called on a valid disk.
+	ldx #$00
 	ldx #$00
 	rts