From ae22606f8158821e678f9d50382051fe2adc3aad Mon Sep 17 00:00:00 2001
From: Nathaniel Walizer <robots.are.love@gmail.com>
Date: Wed, 19 Mar 2025 10:47:23 -0700
Subject: [PATCH] ARM/STM32 Compatability improvements

 - Rename DEBUG to NESE_DEBUG
 - Split out allocators for internal RAM
 - SDL flushing (GPU compat)
 - Porting notes
---
 src/cart.c       |  7 ++++---
 src/f6502.c      |  2 +-
 src/linux/port.c | 30 ++++++++++++++++++++++++++++++
 src/log.h        |  8 ++++----
 src/map/map001.c |  2 +-
 src/map/map004.c |  2 +-
 src/nes.c        |  2 +-
 src/port.h       |  4 ++++
 src/ppu.c        |  2 +-
 9 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/src/cart.c b/src/cart.c
index f0c14da..598b5b4 100644
--- a/src/cart.c
+++ b/src/cart.c
@@ -2,10 +2,11 @@
 #include <string.h>
 
 #include "cart.h"
+#include "port.h"
 
 
 #ifdef DEBUG_CART
-#define DEBUG "Cart"
+#define NESE_DEBUG "Cart"
 #endif
 #include "log.h"
 
@@ -64,7 +65,7 @@ int nes_cart_load_mem(void* data, int size, nes* sys) {
             if (hdr->chr_size_lsb <= 0) {
                 int chr_size = mapper->max_chr_banks *
                                NES_CHR_ROM_PAGE_SIZE;
-                mem->ppu.chr_ram = calloc(1, chr_size);
+                mem->ppu.chr_ram = nese_alloc_gpu(chr_size);
                 LOGI("CHR RAM: %d kB", chr_size / 1024);
                 mem->ppu.chr = mem->ppu.chr_ram;
                 mem->ppu.n_chr_banks = chr_size /
@@ -75,7 +76,7 @@ int nes_cart_load_mem(void* data, int size, nes* sys) {
             mem->mapper = *mapper;
             mem->mapper.irq_arg = &sys->core;
             mem->mapper.irq_callback = (void(*)(void*, bool))f6502_set_IRQ;
-            mem->mapper.data = calloc(1, mapper->data_size);
+            mem->mapper.data = nese_alloc(mapper->data_size);
             if (NULL == mem->mapper.data) {
                 LOGE("Failed to allocate mapper data");
                 status = -1;
diff --git a/src/f6502.c b/src/f6502.c
index 0751de7..fd27754 100644
--- a/src/f6502.c
+++ b/src/f6502.c
@@ -16,7 +16,7 @@
         (type *)((char *)__mptr - offsetof(type,member));})
 #endif
 
-//#define DEBUG "Core"
+//#define NESE_DEBUG "Core"
 #include "log.h"
 
 
diff --git a/src/linux/port.c b/src/linux/port.c
index 1064d7d..98b7139 100644
--- a/src/linux/port.c
+++ b/src/linux/port.c
@@ -15,6 +15,10 @@
 #include "log.h"
 
 
+/* OS-specific file operations
+ * Memory mapping specifically needs to be ported for each OS
+ */
+
 static void* nese_map_file(FILE* file, int size) {
     void* addr = mmap(NULL, size, PROT_READ, MAP_SHARED,
                       fileno(file), 0);
@@ -38,6 +42,29 @@ static int nese_file_size(FILE* file) {
 }
 
 
+/* Platform-specific allocation
+ * GPU and CPU refer to emulator memory spaces
+ * Note: GPU (and possibly CPU) regions may need
+ * to be placed into internal ram for performance
+ */
+
+void* nese_alloc_gpu(int size) {
+    return calloc(1, size);
+}
+
+void* nese_alloc_cpu(int size) {
+    return calloc(1, size);
+}
+
+void* nese_alloc(int size) {
+    return calloc(1, size);
+}
+
+
+/* SDL-specific init and entry point
+ * This should be maximally reusable across platforms
+ */
+
 typedef struct {
     const char* filename;
     FILE* file;
@@ -137,6 +164,8 @@ int nese_frame_start(void* plat_data, uint8_t background) {
     platform_data* plat = (platform_data*)plat_data;
 
     SDL_Color ext = nes_palette[background];
+    // TODO: Compose color according to GPU format?
+    // Why are R/B reversed on STM32?
     SDL_FillRect(plat->target, NULL, ((int)ext.r << 16) |
                                      ((int)ext.g << 8) | ext.b);
 
@@ -218,6 +247,7 @@ int nese_frame_ready(void* plat_data) {
     }
     putc('\n', stdout);
 */
+    SDL_RenderFlush(plat->renderer);
 
     SDL_BlitSurface(plat->screen, NULL, plat->target, NULL);
 
diff --git a/src/log.h b/src/log.h
index 6653590..a6b9749 100644
--- a/src/log.h
+++ b/src/log.h
@@ -1,15 +1,15 @@
 #include <stdio.h>
 
 
-#ifdef DEBUG
+#ifdef NESE_DEBUG
 
-#define LOG(l, f, ...)  fprintf(stderr, l ": " DEBUG ": " f "\n" __VA_OPT__(,) __VA_ARGS__)
+#define LOG(l, f, ...)  fprintf(stderr, l ": " NESE_DEBUG ": " f "\n" __VA_OPT__(,) __VA_ARGS__)
 
-#else // !DEBUG
+#else // !NESE_DEBUG
 
 #define LOG(...)
 
-#endif // DEBUG
+#endif // NESE_DEBUG
 
 
 #define LOGE(f, ...) LOG("E", f, __VA_ARGS__)
diff --git a/src/map/map001.c b/src/map/map001.c
index 4ca4c44..b5254f3 100644
--- a/src/map/map001.c
+++ b/src/map/map001.c
@@ -1,6 +1,6 @@
 #include "memory.h"
 
-//#define DEBUG "MMC1"
+//#define NESE_DEBUG "MMC1"
 #include "log.h"
 
 
diff --git a/src/map/map004.c b/src/map/map004.c
index 3203cef..a1a7594 100644
--- a/src/map/map004.c
+++ b/src/map/map004.c
@@ -1,6 +1,6 @@
 #include "memory.h"
 
-#define DEBUG "MMC3"
+#define NESE_DEBUG "MMC3"
 #include "log.h"
 
 
diff --git a/src/nes.c b/src/nes.c
index 8b12a71..72bee51 100644
--- a/src/nes.c
+++ b/src/nes.c
@@ -3,7 +3,7 @@
 #include "nes.h"
 #include "port.h"
 
-//#define DEBUG "NES"
+//#define NESE_DEBUG "NES"
 #include "log.h"
 
 
diff --git a/src/port.h b/src/port.h
index a522a7c..4d91896 100644
--- a/src/port.h
+++ b/src/port.h
@@ -11,5 +11,9 @@ int nese_line_ready(void*, uint8_t* buffer, int line);
 int nese_frame_ready(void*);
 int nese_update_input(void*, nes_Input*);
 
+void* nese_alloc_gpu(int);
+void* nese_alloc_cpu(int);
+void* nese_alloc(int);
+
 
 #endif // NESE_PORT_H_
diff --git a/src/ppu.c b/src/ppu.c
index 6079195..d14f1e3 100644
--- a/src/ppu.c
+++ b/src/ppu.c
@@ -2,7 +2,7 @@
 
 #include "ppu.h"
 
-//#define DEBUG "PPU"
+//#define NESE_DEBUG "PPU"
 #include "log.h"