Merge remote-tracking branch

'origin/GP-713_ghidra1_ELF_PowerPC_EMB_Relocation--SQUASHED'
(Closes #890)

Ghidra/Processors/PowerPC/data/languages/ppc_32_be.cspec

@@ -87,6 +87,9 @@
         </pentry>
       </output>
       <unaffected>
+        <register name="r1"/>  <!-- stack pointer -->
+        <register name="r2"/>  <!-- _SDA2_BASE_ -->
+      	<register name="r13"/> <!-- _SDA_BASE_  -->
         <register name="r14"/>
         <register name="r15"/>
         <register name="r16"/>
@@ -105,7 +108,8 @@
         <register name="r29"/>
         <register name="r30"/>
         <register name="r31"/>
-        <register name="r1"/>
+        <register name="cr2"/>
+        <register name="cr3"/>
         <register name="cr4"/>
       </unaffected>
     </prototype>

Ghidra/Processors/PowerPC/data/languages/ppc_32_le.cspec

@@ -87,6 +87,9 @@
         </pentry>
       </output>
       <unaffected>
+        <register name="r1"/>  <!-- stack pointer -->
+        <register name="r2"/>  <!-- _SDA2_BASE_ -->
+      	<register name="r13"/> <!-- _SDA_BASE_  -->
         <register name="r14"/>
         <register name="r15"/>
         <register name="r16"/>
@@ -105,7 +108,9 @@
         <register name="r29"/>
         <register name="r30"/>
         <register name="r31"/>
-        <register name="r1"/>
+        <register name="cr2"/>
+        <register name="cr3"/>
+        <register name="cr4"/>
       </unaffected>
     </prototype>
   </default_proto>

Ghidra/Processors/PowerPC/data/languages/ppc_isa.sinc

@@ -1733,12 +1733,20 @@ define pcodeop stdcixOp;
 } 
 
 # binutils-descr: "lq",		OP(56),		OP_MASK,     POWER4,	PPC476,		{RTQ, DQ, RAQ}
-define pcodeop lqOp;
 # ISA-cmt: lq - Load Quadword
 # ISA-info: lq - Form "DQ" Page 751 Category "LSQ"
 # binutils: power4.d:  +0:	e0 83 00 00 	lq      r4,0\(r3\)
 # binutils: power4.d:  +4:	e0 83 00 00 	lq      r4,0\(r3\)
-:lq RT,A,DQ is $(NOTVLE) & OP=56 & RT & A & DQ & BITS_0_3=0  { RT = lqOp(RT,A); } 
+:lq RT,A,DQ is $(NOTVLE) & OP=56 & RT & Dp & A & DQ & BITS_0_3=0 & regp [regpset = Dp+1;] { 
+	ea:$(REGISTER_SIZE) = A + sext(DQ:2 << 4);
+@if ENDIAN == "big"
+	RT = *:$(REGISTER_SIZE) ea;
+	regp = *:$(REGISTER_SIZE) (ea + $(REGISTER_SIZE));
+@else
+	RT = *:$(REGISTER_SIZE) (ea + $(REGISTER_SIZE));
+	regp = *:$(REGISTER_SIZE) ea;
+@endif
+} 
 
 define pcodeop lvepxOp;
 :lvepx RT,A,B is OP=31 & RT & A & B & XOP_1_10=295 & BIT_0=0  { RT = lvepxOp(RT,A,B); } 
@@ -2038,7 +2046,6 @@ define pcodeop stfdpOp;
 } 
 
 # binutils-descr: "stq",		DSO(62,2),	DS_MASK,     POWER4,	PPC476,		{RSQ, DS, RA0}
-define pcodeop stqOp;
 # ISA-cmt: stq - Store Quadword
 # ISA-info: stq - Form "DS" Page 751 Category "LSQ"
 # binutils: power4.d:  +50:	f8 c7 00 02 	stq     r6,0\(r7\)
@@ -2046,9 +2053,15 @@ define pcodeop stqOp;
 # binutils: power4.d:  +58:	f8 c7 ff f2 	stq     r6,-16\(r7\)
 # binutils: power4.d:  +5c:	f8 c7 80 02 	stq     r6,-32768\(r7\)
 # binutils: power4.d:  +60:	f8 c7 7f f2 	stq     r6,32752\(r7\)
-:stq S,RA_OR_ZERO,DS is $(NOTVLE) & OP=62 & S & RA_OR_ZERO & DS & BITS_0_1=2  {
+:stq RS,RA_OR_ZERO,DS is $(NOTVLE) & OP=62 & RS & Dp & RA_OR_ZERO & DS & BITS_0_1=2 & regp [regpset = Dp+1;] {
-	EA:$(REGISTER_SIZE) = RA_OR_ZERO + sext(DS:2 << 2);
+	ea:$(REGISTER_SIZE) = RA_OR_ZERO + sext(DS:2 << 2);
-	*:16 EA = stqOp(S,RA_OR_ZERO,DS:2);
+@if ENDIAN == "big"
+	*:$(REGISTER_SIZE) ea = RS;
+	*:$(REGISTER_SIZE) (ea + $(REGISTER_SIZE)) = regp;
+@else
+	*:$(REGISTER_SIZE) (ea + $(REGISTER_SIZE)) = RS;
+	*:$(REGISTER_SIZE) ea = regp;
+@endif
 } 
 
 define pcodeop stvepxOp;

Ghidra/Processors/PowerPC/src/main/java/ghidra/app/util/bin/format/elf/extend/PowerPC64_ElfExtension.java

@@ -47,11 +47,22 @@ public class PowerPC64_ElfExtension extends ElfExtension {
 	public static final ElfDynamicType DT_PPC64_OPDSZ = new ElfDynamicType(0x70000002,
 		"DT_PPC64_OPDSZ", "Specify the size of the .opd section", ElfDynamicValueType.ADDRESS);
 	public static final ElfDynamicType DT_PPC64_OPT = new ElfDynamicType(0x70000003, "DT_PPC64_OPT",
-		"Specify whether various optimisations are possible", ElfDynamicValueType.VALUE);
+		"Specify whether various optimizations are possible", ElfDynamicValueType.VALUE);
 
 	// PPC64 ABI Version Flag Bits contained within ElfHeader e_flags
 	private static final int EF_PPC64_ABI = 3;
 
+	// DT_PPC64_OPT bits
+	private static final int PPC64_OPT_TLS = 1;
+	private static final int PPC64_OPT_MULTI_TOC = 2;
+	private static final int PPC64_OPT_LOCALENTRY = 4;
+
+	// ELFv2 ABI symbol st_other bits
+	//   STO_PPC64_LOCAL specifies the number of instructions between a
+	//   function's global entry point and local entry point
+	private static final int STO_PPC64_LOCAL_BIT = 5;
+	private static final int STO_PPC64_LOCAL_MASK = 0xE0;
+
 	public static final String TOC_BASE = "TOC_BASE"; // injected symbol to mark global TOC_BASE
 
 	@Override

Ghidra/Processors/PowerPC/src/main/java/ghidra/app/util/bin/format/elf/extend/PowerPC_ElfExtension.java

@@ -46,6 +46,11 @@ public class PowerPC_ElfExtension extends ElfExtension {
 	public static final ElfDynamicType DT_PPC_OPT = new ElfDynamicType(0x70000001, "DT_PPC_OPT",
 		"Specify that tls descriptors should be optimized", ElfDynamicValueType.VALUE);
 
+	// ELF header flags
+	private static final int EF_PPC_EMB = 0x80000000;				// PowerPC embedded flag
+	private static final int EF_PPC_RELOCATABLE = 0x00010000;
+	private static final int EF_PPC_RELOCATABLE_LIB = 0x00008000;
+
 	// Program header (segment) flags
 	private static final int PF_PPC_VLE = 0x10000000;
 

Ghidra/Processors/PowerPC/src/main/java/ghidra/app/util/bin/format/elf/relocation/PowerPC64_ElfRelocationConstants.java

@@ -122,6 +122,44 @@ public class PowerPC64_ElfRelocationConstants {
 	public static final int R_PPC64_DTPREL16_HIGHEST = 105; // half16    #highest(@dtprel)
 	public static final int R_PPC64_DTPREL16_HIGHESTA = 106; // half16   #highesta(@dtprel)
 
+	public static final int R_PPC64_PLTSEQ_NOTOC = 121;
+	public static final int R_PPC64_PLTCALL_NOTOC = 122;
+	public static final int R_PPC64_PCREL_OPT = 123;
+
+	public static final int R_PPC64_D34 = 128;
+	public static final int R_PPC64_D34_LO = 129;
+	public static final int R_PPC64_D34_HI30 = 130;
+	public static final int R_PPC64_D34_HA30 = 131;
+	public static final int R_PPC64_PCREL34 = 132;
+	public static final int R_PPC64_GOT_PCREL34 = 133;
+	public static final int R_PPC64_PLT_PCREL34 = 134;
+	public static final int R_PPC64_PLT_PCREL34_NOTOC = 135;
+	public static final int R_PPC64_ADDR16_HIGHER34 = 136;
+	public static final int R_PPC64_ADDR16_HIGHERA34 = 137;
+	public static final int R_PPC64_ADDR16_HIGHEST34 = 138;
+	public static final int R_PPC64_ADDR16_HIGHESTA34 = 139;
+	public static final int R_PPC64_REL16_HIGHER34 = 140;
+	public static final int R_PPC64_REL16_HIGHERA34 = 141;
+	public static final int R_PPC64_REL16_HIGHEST34 = 142;
+	public static final int R_PPC64_REL16_HIGHESTA34 = 143;
+	public static final int R_PPC64_D28 = 144;
+	public static final int R_PPC64_PCREL28 = 145;
+	public static final int R_PPC64_TPREL34 = 146;
+	public static final int R_PPC64_DTPREL34 = 147;
+	public static final int R_PPC64_GOT_TLSGD_PCREL34 = 148;
+	public static final int R_PPC64_GOT_TLSLD_PCREL34 = 149;
+	public static final int R_PPC64_GOT_TPREL_PCREL34 = 150;
+	public static final int R_PPC64_GOT_DTPREL_PCREL34 = 151;
+
+	public static final int R_PPC64_REL16_HIGH = 240;
+	public static final int R_PPC64_REL16_HIGHA = 241;
+	public static final int R_PPC64_REL16_HIGHER = 242;
+	public static final int R_PPC64_REL16_HIGHERA = 243;
+	public static final int R_PPC64_REL16_HIGHEST = 244;
+	public static final int R_PPC64_REL16_HIGHESTA = 245;
+
+	public static final int R_PPC64_JMP_IREL = 247;
+
 	// Masks for manipulating Power PC relocation targets
 	public static final int PPC64_WORD32 = 0xFFFFFFFF;
 	public static final int PPC64_WORD30 = 0xFFFFFFFC;

Ghidra/Processors/PowerPC/src/main/java/ghidra/app/util/bin/format/elf/relocation/PowerPC_ElfRelocationConstants.java

@@ -58,6 +58,85 @@ public class PowerPC_ElfRelocationConstants {
 	public static final int R_PPC_SECTOFF_HA = 36; // half16 #ha(R + A)
 	public static final int R_PPC_ADDR30 = 37; // word30 (S + A - P) >> 2
 
+	public static final int R_POWERPC_TLS = 67;
+	public static final int R_POWERPC_DTPMOD = 68;
+	public static final int R_POWERPC_TPREL16 = 69;
+	public static final int R_POWERPC_TPREL16_LO = 70;
+	public static final int R_POWERPC_TPREL16_HI = 71;
+	public static final int R_POWERPC_TPREL16_HA = 72;
+	public static final int R_POWERPC_TPREL = 73;
+	public static final int R_POWERPC_DTPREL16 = 74;
+	public static final int R_POWERPC_DTPREL16_LO = 75;
+	public static final int R_POWERPC_DTPREL16_HI = 76;
+	public static final int R_POWERPC_DTPREL16_HA = 77;
+	public static final int R_POWERPC_DTPREL = 78;
+	public static final int R_POWERPC_GOT_TLSGD16 = 79;
+	public static final int R_POWERPC_GOT_TLSGD16_LO = 80;
+	public static final int R_POWERPC_GOT_TLSGD16_HI = 81;
+	public static final int R_POWERPC_GOT_TLSGD16_HA = 82;
+	public static final int R_POWERPC_GOT_TLSLD16 = 83;
+	public static final int R_POWERPC_GOT_TLSLD16_LO = 84;
+	public static final int R_POWERPC_GOT_TLSLD16_HI = 85;
+	public static final int R_POWERPC_GOT_TLSLD16_HA = 86;
+	public static final int R_POWERPC_GOT_TPREL16 = 87;
+	public static final int R_POWERPC_GOT_TPREL16_LO = 88;
+	public static final int R_POWERPC_GOT_TPREL16_HI = 89;
+	public static final int R_POWERPC_GOT_TPREL16_HA = 90;
+	public static final int R_POWERPC_GOT_DTPREL16 = 91;
+	public static final int R_POWERPC_GOT_DTPREL16_LO = 92;
+	public static final int R_POWERPC_GOT_DTPREL16_HI = 93;
+	public static final int R_POWERPC_GOT_DTPREL16_HA = 94;
+	public static final int R_PPC_TLSGD = 95;
+	public static final int R_PPC_TLSLD = 96;
+
+	public static final int R_PPC_EMB_NADDR32 = 101; // uword32 (A - S)
+	public static final int R_PPC_EMB_NADDR16 = 102; // uhalf16 (A - S)
+	public static final int R_PPC_EMB_NADDR16_LO = 103; // uhalf16 #lo(A - S)
+	public static final int R_PPC_EMB_NADDR16_HI = 104; // uhalf16 #hi(A - S)
+	public static final int R_PPC_EMB_NADDR16_HA = 105; // uhalf16 #ha(A - S)
+	public static final int R_PPC_EMB_SDAI16 = 106; // uhalf16 T
+	public static final int R_PPC_EMB_SDA2I16 = 107; // uhalf16 U
+	public static final int R_PPC_EMB_SDA2REL = 108; // uhalf16 S + A - _SDA2_BASE_
+	public static final int R_PPC_EMB_SDA21 = 109; // ulow21
+	public static final int R_PPC_EMB_MRKREF = 110; // none
+	public static final int R_PPC_EMB_RELSEC16 = 111; // uhalf16 V + A
+	public static final int R_PPC_EMB_RELST_LO = 112; // uhalf16 #lo(W + A)
+	public static final int R_PPC_EMB_RELST_HI = 113; // uhalf16 #hi(W + A)
+	public static final int R_PPC_EMB_RELST_HA = 114; // uhalf16 #ha(W + A)
+	public static final int R_PPC_EMB_BIT_FLD = 115; // uword32
+	public static final int R_PPC_EMB_RELSDA = 116; // uhalf16
+
+	public static final int R_POWERPC_PLTSEQ = 119;
+	public static final int R_POWERPC_PLTCALL = 120;
+
+	public static final int R_PPC_VLE_REL8 = 216;
+	public static final int R_PPC_VLE_REL15 = 217;
+	public static final int R_PPC_VLE_REL24 = 218;
+	public static final int R_PPC_VLE_LO16A = 219;
+	public static final int R_PPC_VLE_LO16D = 220;
+	public static final int R_PPC_VLE_HI16A = 221;
+	public static final int R_PPC_VLE_HI16D = 222;
+	public static final int R_PPC_VLE_HA16A = 223;
+	public static final int R_PPC_VLE_HA16D = 224;
+	public static final int R_PPC_VLE_SDA21 = 225;
+	public static final int R_PPC_VLE_SDA21_LO = 226;
+	public static final int R_PPC_VLE_SDAREL_LO16A = 227;
+	public static final int R_PPC_VLE_SDAREL_LO16D = 228;
+	public static final int R_PPC_VLE_SDAREL_HI16A = 229;
+	public static final int R_PPC_VLE_SDAREL_HI16D = 230;
+	public static final int R_PPC_VLE_SDAREL_HA16A = 231;
+	public static final int R_PPC_VLE_SDAREL_HA16D = 232;
+
+	public static final int R_POWERPC_REL16DX_HA = 246;
+	public static final int R_POWERPC_IRELATIVE = 248;
+	public static final int R_POWERPC_REL16 = 249;
+	public static final int R_POWERPC_REL16_LO = 250;
+	public static final int R_POWERPC_REL16_HI = 251;
+	public static final int R_POWERPC_REL16_HA = 252;
+	public static final int R_POWERPC_GNU_VTINHERIT = 253;
+	public static final int R_POWERPC_GNU_VTENTRY = 254;
+	public static final int R_PPC_TOC16 = 255;
+
 	// Masks for manipulating Power PC relocation targets
 	public static final int PPC_WORD32 = 0xFFFFFFFF;
 	public static final int PPC_WORD30 = 0xFFFFFFFC;

Ghidra/Processors/PowerPC/src/main/java/ghidra/app/util/bin/format/elf/relocation/PowerPC_ElfRelocationHandler.java

@@ -15,14 +15,22 @@
  */
 package ghidra.app.util.bin.format.elf.relocation;
 
+import java.math.BigInteger;
+import java.util.Map;
+
+import com.google.common.base.Predicate;
+
 import ghidra.app.util.bin.format.elf.*;
 import ghidra.app.util.bin.format.elf.extend.PowerPC_ElfExtension;
-import ghidra.program.model.address.Address;
+import ghidra.app.util.importer.MessageLog;
+import ghidra.program.model.address.*;
 import ghidra.program.model.lang.Language;
+import ghidra.program.model.lang.Register;
+import ghidra.program.model.listing.ContextChangeException;
 import ghidra.program.model.listing.Program;
-import ghidra.program.model.mem.Memory;
+import ghidra.program.model.mem.*;
-import ghidra.program.model.mem.MemoryAccessException;
+import ghidra.program.model.symbol.*;
-import ghidra.util.exception.NotFoundException;
+import ghidra.util.exception.*;
 
 public class PowerPC_ElfRelocationHandler extends ElfRelocationHandler {
 
@@ -31,16 +39,25 @@ public class PowerPC_ElfRelocationHandler extends ElfRelocationHandler {
 		return elf.e_machine() == ElfConstants.EM_PPC && elf.is32Bit();
 	}
 
+	@Override
+	public PowerPC_ElfRelocationContext createRelocationContext(ElfLoadHelper loadHelper,
+			ElfRelocationTable relocationTable, Map<ElfSymbol, Address> symbolMap) {
+		return new PowerPC_ElfRelocationContext(this, loadHelper, relocationTable, symbolMap);
+	}
+
 	@Override
 	public void relocate(ElfRelocationContext elfRelocationContext, ElfRelocation relocation,
 			Address relocationAddress) throws MemoryAccessException, NotFoundException {
 
-		ElfHeader elf = elfRelocationContext.getElfHeader();
+		PowerPC_ElfRelocationContext ppcRelocationContext =
+			(PowerPC_ElfRelocationContext) elfRelocationContext;
+
+		ElfHeader elf = ppcRelocationContext.getElfHeader();
 		if (elf.e_machine() != ElfConstants.EM_PPC || !elf.is32Bit()) {
 			return;
 		}
 
-		Program program = elfRelocationContext.getProgram();
+		Program program = ppcRelocationContext.getProgram();
 		Memory memory = program.getMemory();
 
 		int type = relocation.getType();
@@ -49,12 +66,12 @@ public class PowerPC_ElfRelocationHandler extends ElfRelocationHandler {
 		}
 		int symbolIndex = relocation.getSymbolIndex();
 
-		Language language = elfRelocationContext.getProgram().getLanguage();
+		Language language = ppcRelocationContext.getProgram().getLanguage();
 		if (!"PowerPC".equals(language.getProcessor().toString()) ||
 			language.getLanguageDescription().getSize() != 32) {
 			markAsError(program, relocationAddress, Long.toString(type), null,
 				"Unsupported language for 32-bit PowerPC relocation",
-				elfRelocationContext.getLog());
+				ppcRelocationContext.getLog());
 		}
 
 		// NOTE: Based upon glibc source it appears that PowerPC only uses RELA relocations
@@ -72,7 +89,7 @@ public class PowerPC_ElfRelocationHandler extends ElfRelocationHandler {
 //
 //			// Relocation addend already includes original symbol value but needs to account 
 //			// for any image base adjustment
-//			symbolValue = (int) elfRelocationContext.getImageBaseWordAdjustmentOffset();
+//			symbolValue = (int) ppcRelocationContext.getImageBaseWordAdjustmentOffset();
 //		}
 //		else {
 		Address symbolAddr = (elfRelocationContext.getSymbolAddress(sym));
@@ -162,7 +179,7 @@ public class PowerPC_ElfRelocationHandler extends ElfRelocationHandler {
 				memory.setInt(relocationAddress, newValue);
 				break;
 			case PowerPC_ElfRelocationConstants.R_PPC_RELATIVE:
-				newValue = (int) elfRelocationContext.getImageBaseWordAdjustmentOffset() + addend;
+				newValue = (int) ppcRelocationContext.getImageBaseWordAdjustmentOffset() + addend;
 				memory.setInt(relocationAddress, newValue);
 				break;
 			case PowerPC_ElfRelocationConstants.R_PPC_REL32:
@@ -202,15 +219,200 @@ public class PowerPC_ElfRelocationHandler extends ElfRelocationHandler {
 					// not too far away since a fabricated GOT would be in the same block
 					// and we may only have room in the plt for two instructions.
 					markAsUnhandled(program, relocationAddress, type, symbolIndex, symbolName,
-						elfRelocationContext.getLog());
+						ppcRelocationContext.getLog());
 				}
 				break;
+			case PowerPC_ElfRelocationConstants.R_PPC_EMB_SDA21:
+				// NOTE: PPC EABI V1.0 specifies this relocation on a 24-bit field address while 
+				// GNU assumes a 32-bit field address.  We cope with this difference by 
+				// forcing a 32-bit alignment of the relocation address. 
+				long alignedRelocOffset = relocationAddress.getOffset() & ~3;
+				relocationAddress = relocationAddress.getNewAddress(alignedRelocOffset);
+
+				oldValue = memory.getInt(relocationAddress);
+
+				Address symAddr = ppcRelocationContext.getSymbolAddress(sym);
+				MemoryBlock block = memory.getBlock(symAddr);
+				Integer sdaBase = null;
+				Integer gprID = null;
+
+				if (block != null) {
+					String blockName = block.getName();
+					if (".sdata".equals(blockName) || ".sbss".equals(blockName)) {
+						sdaBase = ppcRelocationContext.getSDABase();
+						gprID = 13;
+					}
+					else if (".sdata2".equals(blockName) || ".sbss2".equals(blockName)) {
+						sdaBase = ppcRelocationContext.getSDA2Base();
+						gprID = 2;
+					}
+					else if (".PPC.EMB.sdata0".equals(blockName) ||
+						".PPC.EMB.sbss0".equals(blockName)) {
+						sdaBase = 0;
+						gprID = 0;
+					}
+					else if (MemoryBlock.EXTERNAL_BLOCK_NAME.equals(blockName)) {
+						markAsError(program, relocationAddress, type, sym.getNameAsString(),
+							"Unsupported relocation for external symbol",
+							ppcRelocationContext.getLog());
+						break;
+					}
+				}
+				if (gprID == null || sdaBase == null) {
+					markAsError(program, relocationAddress, type, sym.getNameAsString(),
+						"Failed to identfy appropriate data block", ppcRelocationContext.getLog());
+					break;
+				}
+
+				newValue = (symbolValue - sdaBase + addend) & 0xffff;
+				newValue |= gprID << 16;
+				newValue |= oldValue & 0xffe00000;
+				memory.setInt(relocationAddress, newValue);
+				break;
+
 			default:
 				markAsUnhandled(program, relocationAddress, type, symbolIndex, symbolName,
-					elfRelocationContext.getLog());
+					ppcRelocationContext.getLog());
 				break;
 		}
+	}
+
+	/**
+	 * <code>PowerPC_ElfRelocationContext</code> provides extended relocation context..
+	 */
+	private static class PowerPC_ElfRelocationContext extends ElfRelocationContext {
+
+		private Integer sdaBase;
+		private Integer sda2Base;
+
+		protected PowerPC_ElfRelocationContext(ElfRelocationHandler handler,
+				ElfLoadHelper loadHelper, ElfRelocationTable relocationTable,
+				Map<ElfSymbol, Address> symbolMap) {
+			super(handler, loadHelper, relocationTable, symbolMap);
+		}
+
+		/**
+		 * Get or establish _SDA_BASE_ value and apply as r13 context value to all memory blocks
+		 * with execute permission.
+		 * @return _SDA_BASE_ offset or null if unable to determine or establish
+		 */
+		Integer getSDABase() {
+			if (sdaBase != null) {
+				if (sdaBase == -1) {
+					return null;
+				}
+				return sdaBase;
+			}
+			sdaBase = getBaseOffset("_SDA_BASE_", ".sdata", ".sbss");
+			if (sdaBase == -1) {
+				getLog().appendMsg("ERROR: failed to establish _SDA_BASE_");
+				return null;
+			}
+			setRegisterContext("r13", BigInteger.valueOf(sdaBase), b -> b.isExecute());
+			return sdaBase;
+		}
+
+		/**
+		 * Get or establish _SDA2_BASE_ value and apply as r2 context value to all memory blocks
+		 * with execute permission.
+		 * @return _SDA2_BASE_ offset or null if unable to determine or establish
+		 */
+		Integer getSDA2Base() {
+			if (sda2Base != null) {
+				if (sda2Base == -1) {
+					return null;
+				}
+				return sda2Base;
+			}
+			sda2Base = getBaseOffset("_SDA2_BASE_", ".sdata2", ".sbss2");
+			if (sda2Base == -1) {
+				getLog().appendMsg("ERROR: failed to establish _SDA2_BASE_");
+				return null;
+			}
+			setRegisterContext("r2", BigInteger.valueOf(sda2Base), b -> b.isExecute());
+			return sda2Base;
+		}
+
+		/**
+		 * Apply register context to all memory blocks which satisfy blockPredicate check.
+		 * @param regName register name
+		 * @param value context value
+		 * @param blockPredicate determine which memory blocks get context applied
+		 */
+		private void setRegisterContext(String regName, BigInteger value,
+				Predicate<MemoryBlock> blockPredicate) {
+			Register reg = program.getRegister(regName);
+			for (MemoryBlock block : program.getMemory().getBlocks()) {
+				if (block.isExecute()) {
+					try {
+						program.getProgramContext().setValue(reg, block.getStart(), block.getEnd(),
+							value);
+					}
+					catch (ContextChangeException e) {
+						throw new AssertException(e); // no instructions should exist yet
+					}
+				}
+			}
+		}
+
+		/**
+		 * Establish base offset from symbol or range of specified memory blocks.
+		 * @param symbolName base symbol name
+		 * @param blockNames block names which may be used to establish base range
+		 * @return base offset or -1 on failure
+		 */
+		private Integer getBaseOffset(String symbolName, String... blockNames) {
+
+			MessageLog log = getLog();
+
+			Symbol baseSymbol = SymbolUtilities.getLabelOrFunctionSymbol(program, symbolName,
+				msg -> log.appendMsg(msg));
+			if (baseSymbol != null) {
+				int baseOffset = (int) baseSymbol.getAddress().getOffset();
+				String absString = "";
+				if (baseSymbol.isPinned()) {
+					absString = "absolute ";
+				}
+				log.appendMsg(
+					"Using " + absString + symbolName + " of 0x" + Integer.toHexString(baseOffset));
+				return baseOffset;
+			}
+
+			Memory mem = program.getMemory();
+			AddressSpace defaultSpace = program.getAddressFactory().getDefaultAddressSpace();
+			AddressSet blockSet = new AddressSet();
+			for (String blockName : blockNames) {
+				MemoryBlock block = mem.getBlock(blockName);
+				if (block != null) {
+					if (!block.getStart().getAddressSpace().equals(defaultSpace)) {
+						log.appendMsg("ERROR: " + blockName + " not in default space");
+						return -1;
+					}
+					blockSet.add(block.getStart(), block.getEnd());
+				}
+			}
+			if (blockSet.isEmpty()) {
+				return -1;
+			}
+
+			Address baseAddr = blockSet.getMinAddress();
+			long range = blockSet.getMaxAddress().subtract(baseAddr) + 1;
+			if (range > Short.MAX_VALUE) {
+				// use aligned midpoint of range
+				baseAddr = baseAddr.add((range / 2) & ~0x0f);
+			}
+
+			try {
+				program.getSymbolTable().createLabel(baseAddr, symbolName, SourceType.ANALYSIS);
+			}
+			catch (InvalidInputException e) {
+				throw new AssertException(e);
+			}
+
+			int baseOffset = (int) baseAddr.getOffset();
+			log.appendMsg("Defined " + symbolName + " of 0x" + Integer.toHexString(baseOffset));
+			return baseOffset;
+		}
 
 	}
-
 }