3DS: Implement dynamic plugins

Allows a full build to run on old generation devices

3 files changed, 343 insertions, 0 deletions

diff --git a/backends/plugins/3ds/3ds-provider.cpp b/backends/plugins/3ds/3ds-provider.cpp
new file mode 100644
index 0000000000..fd813669a5
--- /dev/null
+++ b/backends/plugins/3ds/3ds-provider.cpp
@@ -0,0 +1,127 @@
+/* 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#define FORBIDDEN_SYMBOL_ALLOW_ALL
+#include "common/scummsys.h"
+
+#if defined(DYNAMIC_MODULES) && defined(__3DS__)
+
+#include "backends/plugins/3ds/3ds-provider.h"
+#include "backends/plugins/elf/arm-loader.h"
+
+#include "common/debug.h"
+
+#include <3ds.h>
+
+extern uint32 __end__; // End of the main program in memory. Set by the linker.
+
+static uint32 alignUp(uint32 ptr, uint32 align) {
+	return (ptr + align - 1) & ~(align - 1);
+}
+
+class CTRDLObject : public ARMDLObject {
+public:
+	CTRDLObject():
+			ARMDLObject(),
+			_segmentHeapAddress(0) {
+	}
+
+protected:
+	static const uint32 kPageSize = 0x1000;
+
+	uint32 _segmentHeapAddress;
+
+	void flushDataCache(void *ptr, uint32 len) const override {
+		svcFlushProcessDataCache(CUR_PROCESS_HANDLE, ptr, len);
+	}
+
+	void protectMemory(void *ptr, uint32 len, int prot) const override {
+		debug(2, "elfloader: Protecting memory at %p, len %d with %d", ptr, len, prot);
+
+		uint32 ctrFlags = 0;
+		if (prot & PF_R) ctrFlags |= MEMPERM_READ;
+		if (prot & PF_W) ctrFlags |= MEMPERM_WRITE;
+		if (prot & PF_X) ctrFlags |= MEMPERM_EXECUTE;
+
+		// The kernel expects the range to be aligned to page boundaries
+		len = alignUp(len, kPageSize);
+
+		Handle currentHandle;
+		svcDuplicateHandle(&currentHandle, CUR_PROCESS_HANDLE);
+		svcControlProcessMemory(currentHandle, (uint32)ptr, 0, len, MEMOP_PROT, ctrFlags);
+		svcCloseHandle(currentHandle);
+	}
+
+	void *allocateMemory(uint32 align, uint32 size) override {
+		assert(!_segmentHeapAddress); // At the moment we can only load a single segment
+
+		_segmentHeapAddress = (uint32)ARMDLObject::allocateMemory(align, size);
+		if (!_segmentHeapAddress) {
+			return nullptr;
+		}
+
+		size = alignUp(size, kPageSize);
+
+		// The plugin needs to be loaded near the main executable for PC-relative calls
+		// to resolve. The segment is allocated on the heap which not in the +/-32 MB
+		// range of the main executable. So here we map the segment address in the heap
+		// to a virtual address just after the main executable.
+		uint32 segmentNearAddress = alignUp((uint32)&__end__, kPageSize) + kPageSize;
+
+		Handle currentHandle;
+		svcDuplicateHandle(&currentHandle, CUR_PROCESS_HANDLE);
+		Result mapResult = svcControlProcessMemory(currentHandle, segmentNearAddress, _segmentHeapAddress, size, MEMOP_MAP, MemPerm(MEMPERM_READ | MEMPERM_WRITE));
+		svcCloseHandle(currentHandle);
+
+		if (mapResult != 0) {
+			warning("elfloader: unable to map segment memory (%x) near the excutable (%x)", _segmentHeapAddress, segmentNearAddress);
+
+			ARMDLObject::deallocateMemory((void *)_segmentHeapAddress, size);
+			_segmentHeapAddress = 0;
+			return nullptr;
+		}
+
+		return (void *)segmentNearAddress;
+	}
+
+	void deallocateMemory(void *ptr, uint32 size) override {
+		assert(_segmentHeapAddress);
+
+		uint32 alignedSize = alignUp(size, kPageSize);
+
+		Handle currentHandle;
+		svcDuplicateHandle(&currentHandle, CUR_PROCESS_HANDLE);
+		svcControlProcessMemory(currentHandle, (uint32)ptr, _segmentHeapAddress, alignedSize, MEMOP_UNMAP, MemPerm(MEMPERM_READ | MEMPERM_WRITE));
+		svcCloseHandle(currentHandle);
+
+		ARMDLObject::deallocateMemory((void *)_segmentHeapAddress, size);
+
+		_segmentHeapAddress = 0;
+	}
+
+};
+
+Plugin *CTRPluginProvider::createPlugin(const Common::FSNode &node) const {
+	return new TemplatedELFPlugin<CTRDLObject>(node.getPath());
+}
+
+#endif // defined(DYNAMIC_MODULES) && defined(__3DS__)
diff --git a/backends/plugins/3ds/3ds-provider.h b/backends/plugins/3ds/3ds-provider.h
new file mode 100644
index 0000000000..c0125e8aec
--- /dev/null
+++ b/backends/plugins/3ds/3ds-provider.h
@@ -0,0 +1,37 @@
+/* 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#if defined(DYNAMIC_MODULES) && defined(__3DS__)
+
+#ifndef BACKENDS_PLUGINS_3DS_PROVIDER_H
+#define BACKENDS_PLUGINS_3DS_PROVIDER_H
+
+#include "backends/plugins/elf/elf-provider.h"
+
+class CTRPluginProvider : public ELFPluginProvider {
+public:
+	Plugin *createPlugin(const Common::FSNode &node) const;
+};
+
+#endif // BACKENDS_PLUGINS_3DS_PROVIDER_H
+
+#endif // defined(DYNAMIC_MODULES) && defined(__3DS__)
diff --git a/backends/plugins/3ds/plugin.ld b/backends/plugins/3ds/plugin.ld
new file mode 100644
index 0000000000..ae83a7ac2e
--- /dev/null
+++ b/backends/plugins/3ds/plugin.ld
@@ -0,0 +1,179 @@
+OUTPUT_FORMAT("elf32-littlearm", "elf32-bigarm", "elf32-littlearm")
+OUTPUT_ARCH(arm)
+ENTRY(_start)
+
+PHDRS
+{
+	/* ScummVM's elf loader only allows a single segment, at the moment. */
+	plugin PT_LOAD FLAGS(7) /* Read | Write | Execute */;
+}
+
+SECTIONS
+{
+	/* =========== CODE section =========== */
+
+	. = 0;
+
+	.text ALIGN(0x1000) :
+	{
+		/* .text */
+		*(.text)
+		*(.text.*)
+		*(.glue_7)
+		*(.glue_7t)
+		*(.stub)
+		*(.gnu.warning)
+		*(.gnu.linkonce.t*)
+		. = ALIGN(4);
+	} : plugin
+
+	/* =========== RODATA section =========== */
+
+	. = ALIGN(0x1000);
+
+	.rodata :
+	{
+		*(.rodata)
+		*(.roda)
+		*(.rodata.*)
+		*all.rodata*(*)
+		*(.gnu.linkonce.r*)
+		SORT(CONSTRUCTORS)
+		. = ALIGN(4);
+	} : plugin
+
+	.ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } : plugin
+	__exidx_start = .;
+	ARM.exidx : { *(.ARM.exidx* .gnu.linkonce.armexidx.*) } : plugin
+	__exidx_end = .;
+
+	/* =========== DATA section =========== */
+
+	. = ALIGN(0x1000);
+
+	.data :
+	{
+		*(.data)
+		*(.data.*)
+		*(.gnu.linkonce.d*)
+		CONSTRUCTORS
+		. = ALIGN(4);
+	} : plugin
+
+	.tdata ALIGN(4) :
+	{
+		__tdata_lma = .;
+		*(.tdata)
+		*(.tdata.*)
+		*(.gnu.linkonce.td.*)
+		. = ALIGN(4);
+		__tdata_lma_end = .;
+	} : plugin
+
+	.tbss ALIGN(4) :
+	{
+		*(.tbss)
+		*(.tbss.*)
+		*(.gnu.linkonce.tb.*)
+		*(.tcommon)
+		. = ALIGN(4);
+	} : plugin
+
+	.preinit_array ALIGN(4) :
+	{
+		PROVIDE (__preinit_array_start = .);
+		KEEP (*(.preinit_array))
+		PROVIDE (__preinit_array_end = .);
+	} : plugin
+
+	.init_array ALIGN(4) :
+	{
+		PROVIDE (__init_array_start = .);
+		KEEP (*(SORT(.init_array.*)))
+		KEEP (*(.init_array))
+		PROVIDE (__init_array_end = .);
+	} : plugin
+
+	.fini_array ALIGN(4) :
+	{
+		PROVIDE (__fini_array_start = .);
+		KEEP (*(.fini_array))
+		KEEP (*(SORT(.fini_array.*)))
+		PROVIDE (__fini_array_end = .);
+	} : plugin
+
+	.ctors ALIGN(4) :
+	{
+		___plugin_ctors = .;
+		KEEP (*(SORT(.ctors.*)))
+		KEEP (*(.ctors))
+		___plugin_ctors_end = .;
+	} : plugin
+
+	.dtors ALIGN(4) :
+	{
+		___plugin_dtors = .;
+		KEEP (*(SORT(.dtors.*)))
+		KEEP (*(.dtors))
+		___plugin_dtors_end = .;
+	} : plugin
+
+	__bss_start__ = .;
+	.bss ALIGN(4) :
+	{
+		*(.dynbss)
+		*(.bss)
+		*(.bss.*)
+		*(.gnu.linkonce.b*)
+		*(COMMON)
+		. = ALIGN(4);
+
+		/* Reserve space for the TLS segment of the main thread */
+		__tls_start = .;
+		. += + SIZEOF(.tdata) + SIZEOF(.tbss);
+		__tls_end = .;
+	} : plugin
+	__bss_end__ = .;
+
+	__end__ = ABSOLUTE(.) ;
+
+	/* ==================
+	   ==== Metadata ====
+	   ================== */
+
+	/* Discard sections that difficult post-processing */
+	/DISCARD/ : { *(.group .comment .note) }
+
+	/* Stabs debugging sections. */
+	.stab          0 : { *(.stab) }
+	.stabstr       0 : { *(.stabstr) }
+	.stab.excl     0 : { *(.stab.excl) }
+	.stab.exclstr  0 : { *(.stab.exclstr) }
+	.stab.index    0 : { *(.stab.index) }
+	.stab.indexstr 0 : { *(.stab.indexstr) }
+
+	/* DWARF debug sections.
+	   Symbols in the DWARF debugging sections are relative to the beginning
+	   of the section so we begin them at 0. */
+
+	/* DWARF 1 */
+	.debug          0 : { *(.debug) }
+	.line           0 : { *(.line) }
+
+	/* GNU DWARF 1 extensions */
+	.debug_srcinfo  0 : { *(.debug_srcinfo) }
+	.debug_sfnames  0 : { *(.debug_sfnames) }
+
+	/* DWARF 1.1 and DWARF 2 */
+	.debug_aranges  0 : { *(.debug_aranges) }
+	.debug_pubnames 0 : { *(.debug_pubnames) }
+
+	/* DWARF 2 */
+	.debug_info     0 : { *(.debug_info) }
+	.debug_abbrev   0 : { *(.debug_abbrev) }
+	.debug_line     0 : { *(.debug_line) }
+	.debug_frame    0 : { *(.debug_frame) }
+	.debug_str      0 : { *(.debug_str) }
+	.debug_loc      0 : { *(.debug_loc) }
+	.debug_macinfo  0 : { *(.debug_macinfo) }
+}