Adafruit_CPFS compatibility (example included)

examples/file_access/file_access.ino

@@ -0,0 +1,72 @@
+/*
+This example shows how to use PicoDVI and a board's flash filesystem (i.e.
+CIRCUITPY drive) simultaneously. This can be useful for loading graphics
+files, saving game state in emulators, etc. To keep this simple, it's just
+a mash-up of the existing PicoDVI '1bit_text' and Adafruit_CPFS 'simple'
+examples, but the same principles certainly apply to other modes.
+
+To start, you first need to temporarily install CircuitPython on the board
+to initialize the flash filesystem, which can then be loaded up with the
+files you need. https://circuitpython.org/downloads
+With the filesystem prepared, one can then work with the Arduino code...
+
+SUPER IMPORTANT: you MUST have current versions of several libraries and
+the Earle Philhower arduino-pico core installed. Failure to have all the
+right pieces will wipe out any data stored on the drive!
+
+arduino-pico (via Arduino board manager)  3.3.0 or later
+Adafruit_CPFS (via Library manager)       1.0.1 or later
+Adafruit_SPIFlash (")                     4.2.0 or later
+
+That said, it's still a smart idea to keep a backup of any data you install
+on the board. These libraries combined are asking a LOT of the RP2040 chip,
+it's always possible there may be some hiccup and you'll have ot start over
+with the CircuitPython install and drive setup.
+*/
+
+#include <PicoDVI.h>       // For DVI video out
+#include <Adafruit_CPFS.h> // For accessing the CIRCUITPY drive
+
+FatVolume *fs = NULL; // CIRCUITPY flash filesystem, as a FAT pointer
+
+// This example uses 80x30 monochrome text mode. See other PicoDVI examples
+// for color, bitmapped graphics, widescreen, alternate boards, etc.
+DVItext1 display(DVI_RES_640x240p60, adafruit_feather_dvi_cfg);
+
+void setup() { // Runs once on startup
+  pinMode(LED_BUILTIN, OUTPUT);
+
+  // Start the CIRCUITPY flash filesystem. SUPER IMPORTANT: NOTICE THE
+  // EXTRA PARAMETERS HERE. This is REQUIRED when using PicoDVI and
+  // Adafruit_CPFS together.
+  fs = Adafruit_CPFS::begin(-1, NULL, false);
+
+  if (!display.begin()) { // Start DVI, slow blink LED if insufficient RAM
+    for (;;) digitalWrite(LED_BUILTIN, (millis() / 500) & 1);
+  }
+
+  if (fs == NULL) { // If CIRCUITPY filesystem is missing or malformed...
+    // Show error message & fast blink LED to indicate problem. Full stop.
+    display.println("Can't access board's CIRCUITPY drive.");
+    display.println("Has CircuitPython been previously installed?");
+    for (;;) digitalWrite(LED_BUILTIN, (millis() / 250) & 1);
+  } // else valid CIRCUITPY drive, proceed...
+
+  // As in Adafruit_CPFS 'simple' example, allow USB events to settle...
+  delay(2500);
+  Adafruit_CPFS::change_ack();
+
+  // Then access files and directories using any SdFat calls (open(), etc.)
+
+  // Because fs is a pointer, we use "->" indirection rather than "." access.
+  // display pointer is cast to print_t so ls() treats it just like Serial.
+  fs->ls((print_t *)&display, LS_R | LS_SIZE); // List initial drive contents
+}
+
+void loop() {
+  if (Adafruit_CPFS::changed()) { // Anything changed on CIRCUITPY drive?
+    Adafruit_CPFS::change_ack();  // Got it, thanks.
+    display.println("CIRCUITPY drive contents changed.");
+    fs->ls((print_t *)&display, LS_R | LS_SIZE);  // List updated drive contents
+  }
+}

library.properties

@@ -1,10 +1,10 @@
 name=PicoDVI - Adafruit Fork
-version=1.0.7
+version=1.1.0
 author=Luke Wren (Wren6991)
 maintainer=Adafruit <info@adafruit.com>
 sentence=Arduino library for RP2040 DVI output, based on PicoDVI
 paragraph=Arduino library for RP2040 DVI output, based on PicoDVI
 category=Display
 url=https://github.com/adafruit/PicoDVI
 architectures=rp2040
-depends=Adafruit GFX Library
+depends=Adafruit GFX Library, Adafruit CPFS

src/PicoDVI.cpp

@@ -54,6 +54,27 @@ void PicoDVI::_setup(void) {
     ; // Wait for DVIGFX*::begin() to set this
   dvi_register_irqs_this_core(&dvi0, DMA_IRQ_0);
   dvi_start(&dvi0);
+
+  // This is disabled for now, for a transitional period while folks
+  // might be mixing in older versions of arduino-pico, Adafruit_CPFS
+  // and/or Adafruit_SPIFlash. Once is seems pretty solid that everyone's
+  // using current versions that correctly locate PicoDVI functions in
+  // RAM, this can be activated. Not urgent but a nice-to-have.
+#if 0
+  // Borrowed from CircuitPython: turn off core 1 flash access. Any attempt
+  // after this will hard fault (not good, but preferable to the alternative
+  // which would corrupt the CIRCUITPY flash filesystem if mounted). Linker
+  // file MUST place the following files in RAM or library won't work:
+  // *interp.c.obj *divider.S.obj *PicoDVI.cpp.o *dvi.c.o
+  // (Earle Philhower arduino-pico >= 3.3.0 does this now.)
+  MPU->CTRL = MPU_CTRL_PRIVDEFENA_Msk | MPU_CTRL_ENABLE_Msk;
+  MPU->RNR  = 6;
+  MPU->RBAR = XIP_MAIN_BASE | MPU_RBAR_VALID_Msk;
+  MPU->RASR = MPU_RASR_XN_Msk | MPU_RASR_ENABLE_Msk |
+              (0x1b << MPU_RASR_SIZE_Pos);
+  MPU->RNR  = 7;
+#endif
+
   (*mainloop)(&dvi0);
 }
 
@@ -384,7 +405,7 @@ static void mainlooptext1(struct dvi_inst *inst) {
 // This is a little simpler and might stick with it
 // since nothing important to do in idle func above.
 
-static void mainlooptext1(struct dvi_inst *inst) {
+static void __not_in_flash_func(mainlooptext1)(struct dvi_inst *inst) {
   ((DVItext1 *)gfxptr)->_mainloop();
 }
 

src/font_8x8.h

@@ -3,7 +3,7 @@
 // so all the row 0 bytes for each of 256 chars appear first, then all row 1
 // bytes for each, row 2, etc. Individual character data is not contiguous.
 
-uint8_t font_8x8[] = {
+uint8_t __not_in_flash_func(font_8x8)[] = {
     0x00, 0x7E, 0x7E, 0x6C, 0x10, 0x38, 0x10, 0x00, 0xFF, 0x00, 0xFF, 0x0F,
     0x3C, 0x3F, 0x7F, 0x99, 0x80, 0x02, 0x18, 0x66, 0x7F, 0x3E, 0x00, 0x18,
     0x18, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x6C, 0x6C,