firmware: the GEOS installer and boot-file reader use the shared disk image engine

Source/Teensy/BlockDevice/TRBlockImage.h

@@ -1,49 +1,65 @@
 // SPDX-License-Identifier: MIT
 // A CBM disk image (D64, D71, D81) as the block device's backend: the track and sector the driver
-// sends become an offset in the image file.
+// sends become an offset in the image file, by the shared engine's geometry (docs/Architecture/Disk-Images.md).
 #pragma once
-#include "../GEOS/GeosDiskPatch.h"
+#include "../DiskImage/DiskImage.h"
 #include "TRBlock.h"
 
 #define TRBLOCK_IMAGE_WRITABLE 0x01
 
+// Set Writable, Context and the callbacks, then TRBlockImageOpen. The engine keeps a pointer to the
+// struct, so it stays where it was opened.
 struct TRBlockImage
 {
-   const struct GeosFormat *Format;
-   bool Writable;
+   d64_t Disk;
+   bool Open, Writable;
    void *Context;
    bool (*Read)(void *Context, uint32_t Offset, uint8_t *Block);
    bool (*Write)(void *Context, uint32_t Offset, const uint8_t *Block);
    bool (*Flush)(void *Context);
 };
 
-static inline bool TRBlockImageHasSector(const struct GeosFormat *Format, uint8_t Track, uint8_t Sector)
+FLASHMEM static int TRBlockImageSectorRead(void *Context, uint8_t Track, uint8_t Sector, uint8_t *Block)
 {
-   return Track >= 1 && Track <= Format->Tracks && Sector < GeosSectorsOnTrack(Format, Track);
+   struct TRBlockImage *Image = (struct TRBlockImage *)Context;
+   return Image->Read(Image->Context, (uint32_t)d64_sector_offset(&Image->Disk, Track, Sector), Block) ? 0 : -1;
+}
+
+FLASHMEM static int TRBlockImageSectorWrite(void *Context, uint8_t Track, uint8_t Sector, const uint8_t *Block)
+{
+   struct TRBlockImage *Image = (struct TRBlockImage *)Context;
+   return Image->Write(Image->Context, (uint32_t)d64_sector_offset(&Image->Disk, Track, Sector), Block) ? 0 : -1;
+}
+
+// An error table (one byte per sector after the data) is left unread: a GEOS driver has no status for a
+// sector marked bad, so it gets the sector's bytes, as a drive that read it anyway would give them.
+FLASHMEM static bool TRBlockImageOpen(struct TRBlockImage *Image, uint64_t Size)
+{
+   Image->Open = Size <= SIZE_MAX && !d64_open_exact(&Image->Disk, TRBlockImageSectorRead, Image, (size_t)Size);
+   if (Image->Open && Image->Writable) Image->Disk.write = TRBlockImageSectorWrite;
+   return Image->Open;
 }
 
 FLASHMEM static uint8_t TRBlockImageTransfer(void *Context, bool Write, uint8_t Track, uint8_t Sector, uint8_t *Block)
 {
    struct TRBlockImage *Image = (struct TRBlockImage *)Context;
-   uint32_t Offset;
 
-   if (!Image->Format) return TRBlockNoImage;
-   if (!TRBlockImageHasSector(Image->Format, Track, Sector)) return TRBlockBadAddress;
-   Offset = GeosOffset(Image->Format, Track, Sector);
-   if (!Write) return Image->Read(Image->Context, Offset, Block) ? TRBlockDone : TRBlockReadFailed;
+   if (!Image->Open) return TRBlockNoImage;
+   if (d64_sector_offset(&Image->Disk, Track, Sector) < 0) return TRBlockBadAddress;
+   if (!Write) return d64_block_read(&Image->Disk, Track, Sector, Block) ? TRBlockReadFailed : TRBlockDone;
    if (!Image->Writable) return TRBlockReadOnly;
-   return Image->Write(Image->Context, Offset, Block) ? TRBlockDone : TRBlockWriteFailed;
+   return d64_block_write(&Image->Disk, Track, Sector, Block) ? TRBlockWriteFailed : TRBlockDone;
 }
 
 FLASHMEM static uint8_t TRBlockImageInfo(void *Context, uint8_t *Out)
 {
    struct TRBlockImage *Image = (struct TRBlockImage *)Context;
    uint32_t Blocks;
 
-   if (!Image->Format) return TRBlockNoImage;
-   Blocks = Image->Format->Size / GEOS_SECTOR_SIZE;
+   if (!Image->Open) return TRBlockNoImage;
+   Blocks = (uint32_t)d64_sectors(&Image->Disk);
 
-   Out[0] = (uint8_t)(Image->Format - GeosFormats + 1);
+   Out[0] = (uint8_t)(Image->Disk.fmt + 1);
    Out[1] = Image->Writable ? TRBLOCK_IMAGE_WRITABLE : 0;
    Out[2] = (uint8_t)Blocks;
    Out[3] = (uint8_t)(Blocks >> 8);
@@ -55,7 +71,7 @@ FLASHMEM static uint8_t TRBlockImageFlush(void *Context)
 {
    struct TRBlockImage *Image = (struct TRBlockImage *)Context;
 
-   if (!Image->Format) return TRBlockNoImage;
+   if (!Image->Open) return TRBlockNoImage;
    return Image->Flush(Image->Context) ? TRBlockDone : TRBlockWriteFailed;
 }
 

Source/Teensy/DiskImage/DiskImage.h

@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: MIT
+// The D64/D71/D81 engine that the GEOS support, the TR block device and VDrive share (docs/Architecture/Disk-Images.md).
+// The firmware builds every .ino and the headers they include as one translation unit, and so does each host
+// harness, so the code comes in once, here, behind the guard.
+#pragma once
+#ifdef ARDUINO
+#include <avr/pgmspace.h>
+#ifndef VD_COLD
+#define VD_COLD FLASHMEM
+#endif
+#ifndef D64_FLASH
+#define D64_FLASH PROGMEM
+#endif
+#else
+#define FLASHMEM
+#endif
+
+#include "d64.h"
+#include "d64.c"