From cd3bb3448280d492ff225dfcb8604dc21a7c14e0 Mon Sep 17 00:00:00 2001
From: Jeff Epler <jepler@gmail.com>
Date: Mon, 24 Mar 2025 09:50:47 -0500
Subject: [PATCH] Fix inverse video & support 512x342 w/o psram

---
 fruitjam-build.sh | 12 +++++++++---
 src/main.c        | 21 ++++++++++++---------
 src/video_hstx.c  |  4 ----
 3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/fruitjam-build.sh b/fruitjam-build.sh
index 9e20a80..eaee774 100755
--- a/fruitjam-build.sh
+++ b/fruitjam-build.sh
@@ -11,14 +11,14 @@ DISP_WIDTH=512
 DISP_HEIGHT=342
 MEMSIZE=400
 DISK_IMAGE=""
-CMAKE_ARGS=
+CMAKE_ARGS=""
 
 while getopts "hvd:m:" o; do
     case "$o" in
     (v)
         DISP_WIDTH=640
         DISP_HEIGHT=480
-        CMAKE_ARGS="$CMAKE_ARGS -DUSE_VGA_RES=1 -DHSTX_CKP=12 -DHSTX_D0P=14 -DHSTX_D1P=16 -DHSTX_D2P=18"
+        CMAKE_ARGS="-DUSE_VGA_RES=1"
         ;;
     (m)
         MEMSIZE=$OPTARG
@@ -42,12 +42,17 @@ done
 shift $((OPTIND-1))
 
 TAG=fruitjam_${DISP_WIDTH}x${DISP_HEIGHT}_${MEMSIZE}k
-PSRAM=$((MEMSIZE > 448 || DISP_WIDTH < 640))
+PSRAM=$((MEMSIZE > 400))
 if [ $PSRAM -ne 0 ] ; then
     TAG=${TAG}_psram
     CMAKE_ARGS="$CMAKE_ARGS -DUSE_PSRAM=1"
 fi
 
+MIRROR_FRAMEBUFFER=$((USE_PSRAM || DISP_WIDTH != 640))
+if [ "$MIRROR_FRAMEBUFFER" -eq 0 ]; then
+    CMAKE_ARGS="$CMAKE_ARGS -DHSTX_CKP=12 -DHSTX_D0P=14 -DHSTX_D1P=16 -DHSTX_D2P=18 "
+fi
+
 # Append disk name to build directory if disk image is specified
 if [ -n "$DISK_IMAGE" ] && [ -f "$DISK_IMAGE" ]; then
     # Extract filename without extension
@@ -74,5 +79,6 @@ cmake -S . -B build_${TAG} \
     -DUSE_HSTX=1 \
     -DSD_TX=35 -DSD_RX=36 -DSD_SCK=34 -DSD_CS=39 -DUSE_SD=1 \
     -DUART_TX=44 -DUART_RX=45 -DUART=0 \
+    -DBOARD_FILE=boards/adafruit_fruit_jam.c \
     ${CMAKE_ARGS} "$@"
 make -C build_${TAG} -j$(nproc)
diff --git a/src/main.c b/src/main.c
index 7902641..9f56db1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -82,12 +82,16 @@ static const uint8_t umac_rom[] = {
 };
 
 #if USE_PSRAM
-static uint32_t umac_framebuffer_mirror[640*480/32];
 #define umac_ram ((uint8_t*)0x11000000)
 #else
 static uint8_t umac_ram[RAM_SIZE];
 #endif
 
+#define MIRROR_FRAMEBUFFER (USE_PSRAM || DISP_WIDTH != 640)
+#if MIRROR_FRAMEBUFFER
+static uint32_t umac_framebuffer_mirror[640*480/32];
+#endif
+
 ////////////////////////////////////////////////////////////////////////////////
 
 static void     io_init()
@@ -115,13 +119,13 @@ static int umac_cursor_y = 0;
 static int umac_cursor_button = 0;
 
 #define umac_get_audio_offset() (RAM_SIZE - 768)
-#if USE_PSRAM
+#if MIRROR_FRAMEBUFFER
 static void copy_framebuffer() {
     uint32_t *src = (uint32_t*)(umac_ram + umac_get_fb_offset());
 #if DISP_WIDTH==640 && DISP_HEIGHT==480
     uint32_t *dest = umac_framebuffer_mirror;
     for(int i=0; i<640*480/32; i++) {
-        *dest++ = *src++ ^ 0xfffffffful;
+        *dest++ = *src++;
     }
 #elif DISP_WIDTH==512 && DISP_HEIGHT==342
     #define DISP_XOFFSET ((640 - DISP_WIDTH) / 32 / 2)
@@ -131,7 +135,7 @@ static void copy_framebuffer() {
     for(int i=0; i<DISP_HEIGHT; i++) {
         uint32_t *dest = umac_framebuffer_mirror + (DISP_YOFFSET * LONGS_PER_OUTPUT_ROW + DISP_XOFFSET) + LONGS_PER_OUTPUT_ROW * i;
         for(int j=0; j<LONGS_PER_INPUT_ROW; j++) {
-          *dest++ = *src++ ^ 0xfffffffful;
+          *dest++ = *src++ ^ 0xffffffff;
         }
     }
 #else
@@ -155,7 +159,7 @@ static void     poll_umac()
         pending_vsync |= audio_poll();
 #endif
         if (pending_vsync) {
-#if USE_PSRAM
+#if MIRROR_FRAMEBUFFER
                 copy_framebuffer();
 #endif
                 /* FIXME: Trigger this off actual vsync */
@@ -301,14 +305,13 @@ static void     core1_main()
         printf("Core 1 started\n");
         disc_setup(discs);
 
-#if USE_PSRAM
-        umac_init(umac_ram, (void *)umac_rom, discs);
-        video_init((uint32_t *)(umac_framebuffer_mirror));
-#else
         umac_init(umac_ram, (void *)umac_rom, discs);
         /* Video runs on core 1, i.e. IRQs/DMA are unaffected by
          * core 0's USB activity.
          */
+#if MIRROR_FRAMEBUFFER
+        video_init((uint32_t *)(umac_framebuffer_mirror));
+#else
         video_init((uint32_t *)(umac_ram + umac_get_fb_offset()));
 #endif
 
diff --git a/src/video_hstx.c b/src/video_hstx.c
index fad4f40..91aa910 100644
--- a/src/video_hstx.c
+++ b/src/video_hstx.c
@@ -141,10 +141,6 @@ static void __not_in_flash_func(dma_irq_handler)(void) {
     ch->al3_read_addr_trig = (uintptr_t)active_picodvi->dma_commands;
 }
 
-#if (DISP_WIDTH != 640 || DISP_HEIGHT != 480) && !USE_PSRAM
-#error Only VGA resolution is supported without PSRAM
-#endif
-
 #define REAL_DISP_WIDTH 640
 #define REAL_DISP_HEIGHT 480