From c8c6fc6a4064efb1a69a99fe75b37cdf5944f60f Mon Sep 17 00:00:00 2001
From: jede <jede@oric.org>
Date: Fri, 17 Mar 2023 23:10:15 +0100
Subject: [PATCH] add xfseek

---
 asminc/telestrat.inc     |  2 ++
 libsrc/telestrat/lseek.s | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 libsrc/telestrat/lseek.s

diff --git a/asminc/telestrat.inc b/asminc/telestrat.inc
index 682696887..c57bd3de8 100644
--- a/asminc/telestrat.inc
+++ b/asminc/telestrat.inc
@@ -277,6 +277,8 @@ XRECLK           = $3C          ; Reset clock
 XCLCL            = $3D          ; Close clock
 XWRCLK           = $3E          ; Displays clock in the address in A & Y registers
 
+XFSEEK           = $3F          ; Only in Orix
+
 ; Sound primitives
 XSONPS           = $40          ; Send data to PSG register (14 values)
 XOUPS            = $42          ; Send Oups sound into PSG
diff --git a/libsrc/telestrat/lseek.s b/libsrc/telestrat/lseek.s
new file mode 100644
index 000000000..11d1fad33
--- /dev/null
+++ b/libsrc/telestrat/lseek.s
@@ -0,0 +1,39 @@
+;
+; Jede (jede@oric.org), 2023-03-13
+;
+
+; off_t __fastcall__ lseek(int fd, off_t offset, int whence);
+
+        .export         _lseek
+
+        .include        "telestrat.inc"
+        .include        "zeropage.inc"
+
+        .import         popax
+
+.proc _lseek
+        ; Save whence
+        sta     tmp1
+        ; Skip X
+
+        ; Get offset and store
+
+        jsr     popax
+        sta     tmp2
+        stx     tmp3
+
+        jsr     popax
+        sta     RESB
+        stx     RESB+1
+
+        ; Get FD
+        jsr     popax
+        ; Does not need X
+        sta     RES           ; Save FD
+
+        lda     tmp2
+        ldy     tmp3
+        ldx     tmp1          ; Get whence
+        BRK_TELEMON XFSEEK
+        rts
+.endproc