Initial commit

backends/platform/3ds/allocHeapsOverride.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+// This file largely reuses code from libctru
+// https://github.com/devkitPro/libctru/blob/33a570b1c335cc38e50b7fef6bf4ed840bbd4ab2/libctru/source/system/allocateHeaps.c
+#include <3ds.h>
+
+#define HEAP_SPLIT_SIZE_CAP  (24 << 20) // 24MB
+#define LINEAR_HEAP_SIZE_CAP (32 << 20) // 32MB
+
+// Hack to get the hardware's FCRAM layout ID. It just werks.
+// Layouts 0 through 5 are used exclusively in Old 3DS systems.
+// Layouts 6 through 8 are used exclusively in New 3DS systems.
+#define APPMEMTYPE (*(u32*)0x1FF80030)
+
+extern "C" void __system_allocateHeaps(void) {
+	extern char* fake_heap_start;
+	extern char* fake_heap_end;
+	extern u32 __ctru_heap;
+	extern u32 __ctru_linear_heap;
+	extern u32 __ctru_heap_size;
+	extern u32 __ctru_linear_heap_size;
+	Result rc;
+
+	// Retrieve handle to the resource limit object for our process
+	Handle reslimit = 0;
+	rc = svcGetResourceLimit(&reslimit, CUR_PROCESS_HANDLE);
+	if (R_FAILED(rc))
+		svcBreak(USERBREAK_PANIC);
+
+	// Retrieve information about total/used memory
+	s64 maxCommit = 0, currentCommit = 0;
+	ResourceLimitType reslimitType = RESLIMIT_COMMIT;
+	svcGetResourceLimitLimitValues(&maxCommit, reslimit, &reslimitType, 1); // for APPLICATION this is equal to APPMEMALLOC at all times
+	svcGetResourceLimitCurrentValues(&currentCommit, reslimit, &reslimitType, 1);
+	svcCloseHandle(reslimit);
+
+	// Calculate how much remaining free memory is available
+	u32 remaining = (u32)(maxCommit - currentCommit) &~ 0xFFF;
+
+	__ctru_heap_size = 0;
+	// New 3DS needs more linear memory than Old 3DS to boot up ScummVM; app instantly crashes otherwise.
+	// 0x00A00000 bytes = 10 MiB, for Old 3DS
+	// 0x01400000 bytes = 20 MiB, for New 3DS
+	__ctru_linear_heap_size = APPMEMTYPE < 6 ? 0x00A00000 : 0x01400000;
+	__ctru_heap_size = remaining - __ctru_linear_heap_size;
+
+	// Allocate the application heap
+	rc = svcControlMemory(&__ctru_heap, OS_HEAP_AREA_BEGIN, 0x0, __ctru_heap_size, MEMOP_ALLOC, static_cast<MemPerm>(static_cast<int>(MEMPERM_READ) | static_cast<int>(MEMPERM_WRITE)));
+	if (R_FAILED(rc))
+		svcBreak(USERBREAK_PANIC);
+
+	// Allocate the linear heap
+	rc = svcControlMemory(&__ctru_linear_heap, 0x0, 0x0, __ctru_linear_heap_size, MEMOP_ALLOC_LINEAR, static_cast<MemPerm>(static_cast<int>(MEMPERM_READ) | static_cast<int>(MEMPERM_WRITE)));
+	if (R_FAILED(rc))
+		svcBreak(USERBREAK_PANIC);
+
+	// Mappable allocator init
+	mappableInit(OS_MAP_AREA_BEGIN, OS_MAP_AREA_END);
+
+	// Set up newlib heap
+	fake_heap_start = (char*)__ctru_heap;
+	fake_heap_end = fake_heap_start + __ctru_heap_size;
+
+}