Merge pull request #124 from MotoLegacy/user-memory

Add support for retrieving the amount of free RAM in user partitions.

src/sdk/Makefile.am

@@ -31,7 +31,7 @@ INETHELPER_OBJS = pspSdkLoadInetModules.o pspSdkInetInit.o pspSdkInetTerm.o
 MULT_SRCS = modulemgr_patches.c inethelper.c
 MULT_OBJS = $(MODULEMGR_PATCHES_OBJS) $(INETHELPER_OBJS)
 
-libpspsdk_a_SOURCES = query_mod.c loadmodule.c fixup.c threadutils.c interrupt.S k1set.S fpu.S $(MULT_SRCS)
+libpspsdk_a_SOURCES = query_mod.c loadmodule.c fixup.c threadutils.c memory.c interrupt.S k1set.S fpu.S $(MULT_SRCS)
 libpspsdk_a_LIBADD  = $(MULT_OBJS)
 
 $(MODULEMGR_PATCHES_OBJS): modulemgr_patches.c

src/sdk/memory.c

@@ -0,0 +1,100 @@
+/*
+ * PSP Software Development Kit - https://github.com/pspdev
+ * -----------------------------------------------------------------------
+ * Licensed under the BSD license, see LICENSE in PSPSDK root for details.
+ *
+ * memory.c - Code to get accurate reporting of available (video) memory.
+ *
+ * Copyright (c) 2023 Ivy Bowling <motolegacy@proton.me>
+ *
+ */
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <pspsdk.h>
+
+static u32 _pspSdkGetMaxLineareMemorySize(void)
+{
+    u32 size, blocksize;
+    u8 *ram;
+
+    size = 0;
+    blocksize = 1024 * 1024; // 1 kB
+
+    while (blocksize)
+    {
+        /* Increase the size by the block */
+        size += blocksize;
+        ram = (u8*) malloc(size);
+
+        if (!ram)
+        {
+            size -= blocksize;
+            blocksize >>= 1;
+        }
+        else
+        {
+            free(ram);
+        }
+    }
+
+    return size;
+}
+
+SceSize pspSdkTotalFreeUserMemSize(void)
+{
+    u8 **ram, **temp;
+    u32 size, count, x;
+
+    ram = NULL;
+    size = count = 0;
+
+    int intc = pspSdkDisableInterrupts();
+
+    while (1) 
+    {
+        /* Check entry size */
+        if (!(count % 10))
+        {
+            /* Allocate more entries if needed */
+            temp = (u8**) realloc(ram, sizeof(u8*) * (count + 10));
+
+            if (!temp)
+                break;
+
+            /* Update entries and their size */
+            ram = temp;
+            size += (sizeof(u8*) * 10);
+        }
+
+        x = _pspSdkGetMaxLineareMemorySize();
+
+        if (!x)
+            break;
+
+        /* Try to do the memory allocation */
+        ram[count] = (u8*) malloc(x);
+
+        if (!ram[count])
+            break;
+
+        size += x;
+        count++;
+    }
+
+    /* Free everything we've allocated */
+    if (ram)
+    {
+        for (x = 0; x < count; x++)
+        {
+            free(ram[x]);
+        }
+
+        free(ram);
+    }
+
+    pspSdkEnableInterrupts(intc);
+
+    /* Amount we were able to allocate before running out, in bytes. */
+    return size;
+}

src/sdk/pspsdk.h

@@ -286,6 +286,17 @@ unsigned int pspSdkGetK1(void);
  */
 void pspSdkDisableFPUExceptions(void);
 
+/**
+ * Gets the amount of memory available in the user partition(s).
+ * 
+ * @note This is not to be confused with sceKernelTotalFreeMemSize, which
+ * rather contradictorily only returns the amount of memory free in the
+ * kernel memory partition.
+ * 
+ * @return The amount of user memory available, in bytes.
+ */
+SceSize pspSdkTotalFreeUserMemSize(void);
+
 /**@}*/
 
 #ifdef __cplusplus