From 9df5355e31c1bba08a83265e1be01090f62df631 Mon Sep 17 00:00:00 2001
From: Stefan Arentz <stefan@arentz.ca>
Date: Mon, 9 Jan 2017 21:39:55 -0500
Subject: [PATCH] Fixes #82 Support nib files

---
 src/dsk.c | 48 ++++++++++++++++++++++++++++++++++++++++--------
 src/dsk.h | 12 +++++++-----
 2 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/src/dsk.c b/src/dsk.c
index 8fcef36..2316825 100644
--- a/src/dsk.c
+++ b/src/dsk.c
@@ -429,9 +429,23 @@ struct ewm_dsk_t *ewm_dsk_create(struct cpu_t *cpu) {
 }
 
 int ewm_dsk_set_disk_data(struct ewm_dsk_t *dsk, uint8_t index, bool readonly, void *data, size_t length, int type) {
-   assert(type == EWM_DSK_TYPE_DO || type == EWM_DSK_TYPE_PO);
-   assert(index < 2);
-   assert(length == (EWM_DSK_TRACKS * EWM_DSK_SECTORS * EWM_DSK_SECTOR_SIZE));
+   if (type == EWM_DSK_TYPE_UNKNOWN) {
+      return -1;
+   }
+
+   if (index > 1) {
+      return -1;
+   }
+
+   if (type == EWM_DSK_TYPE_DO || type == EWM_DSK_TYPE_PO) {
+      if (length != (EWM_DSK_TRACKS * EWM_DSK_SECTORS * 256)) {
+         return -1;
+      }
+   } else if (type == EWM_DSK_TYPE_NIB) {
+      if (length != (EWM_DSK_TRACKS * EWM_DSK_NIBBLES_PER_TRACK)) {
+         return -1;
+      }
+   }
 
    struct ewm_dsk_drive_t *drive = &dsk->drives[index];
 
@@ -451,8 +465,16 @@ int ewm_dsk_set_disk_data(struct ewm_dsk_t *dsk, uint8_t index, bool readonly, v
    drive->readonly = readonly;
    drive->dirty = false;
 
-   for (int t = 0; t < EWM_DSK_TRACKS; t++) {
-      drive->tracks[t] = dsk_convert_track(dsk, drive, data, t, type);
+   if (type == EWM_DSK_TYPE_DO || type == EWM_DSK_TYPE_PO) {
+      for (int t = 0; t < EWM_DSK_TRACKS; t++) {
+         drive->tracks[t] = dsk_convert_track(dsk, drive, data, t, type);
+      }
+   } else if (type == EWM_DSK_TYPE_NIB) {
+      for (int t = 0; t < EWM_DSK_TRACKS; t++) {
+         drive->tracks[t].length = 6656;
+         drive->tracks[t].data = malloc(6656);
+         memcpy(drive->tracks[t].data, data + (t * 6656), 6656);
+      }
    }
 
    return 0;
@@ -465,6 +487,9 @@ static int ewm_dsk_type_from_path(char *path) {
    if (ewm_utl_endswith(path, ".po")) {
       return EWM_DSK_TYPE_PO;
    }
+   if (ewm_utl_endswith(path, ".nib")) {
+      return EWM_DSK_TYPE_NIB;
+   }
    return EWM_DSK_TYPE_UNKNOWN;
 }
 
@@ -485,9 +510,16 @@ int ewm_dsk_set_disk_file(struct ewm_dsk_t *dsk, uint8_t drive, bool readonly, c
       return -1;
    }
 
-   if (file_info.st_size != (EWM_DSK_TRACKS * EWM_DSK_SECTORS * 256)) {
-      close(fd);
-      return -1;
+   if (type == EWM_DSK_TYPE_DO || type == EWM_DSK_TYPE_PO) {
+      if (file_info.st_size != (EWM_DSK_TRACKS * EWM_DSK_SECTORS * 256)) {
+         close(fd);
+         return -1;
+      }
+   } else if (type == EWM_DSK_TYPE_NIB) {
+      if (file_info.st_size != (EWM_DSK_TRACKS * EWM_DSK_NIBBLES_PER_TRACK)) {
+         close(fd);
+         return -1;
+      }
    }
 
    char *data = calloc(file_info.st_size, 1);
diff --git a/src/dsk.h b/src/dsk.h
index e86db75..d63fa70 100644
--- a/src/dsk.h
+++ b/src/dsk.h
@@ -29,12 +29,13 @@
 struct cpu_t;
 struct mem_t;
 
-#define EWM_DSK_DRIVE1 0
-#define EWM_DSK_DRIVE2 1
+#define EWM_DSK_DRIVE1 (0)
+#define EWM_DSK_DRIVE2 (1)
 
-#define EWM_DSK_TRACKS 35
-#define EWM_DSK_SECTORS 16
-#define EWM_DSK_SECTOR_SIZE 256
+#define EWM_DSK_TRACKS (35)
+#define EWM_DSK_SECTORS (16)
+#define EWM_DSK_SECTOR_SIZE (256)
+#define EWM_DSK_NIBBLES_PER_TRACK (6656)
 
 struct ewm_dsk_track_t {
    int length;
@@ -65,6 +66,7 @@ struct ewm_dsk_t {
 #define EWM_DSK_TYPE_UNKNOWN (-1)
 #define EWM_DSK_TYPE_DO (0)
 #define EWM_DSK_TYPE_PO (1)
+#define EWM_DSK_TYPE_NIB (2)
 
 struct ewm_dsk_t *ewm_dsk_create(struct cpu_t *cpu);
 int ewm_dsk_set_disk_data(struct ewm_dsk_t *dsk, uint8_t index, bool readonly, void *data, size_t length, int type);