linux/context.*: Add missing files

core/linux/context.cpp

@@ -0,0 +1,46 @@
+#include "context.h"
+
+#if defined(_ANDROID)
+#include <asm/sigcontext.h>
+#else
+#include <ucontext.h>
+#endif
+
+
+//////
+
+#define MCTX(p) (((ucontext_t *)(segfault_ctx))->uc_mcontext.p)
+template <typename Ta, typename Tb>
+void swap(Ta& a, Tb& b, bool reverse) {
+	if (reverse) {
+		b = a;
+	}
+	else {
+		a = b;
+	}
+}
+
+void context_segfault(rei_host_context_t* reictx, void* segfault_ctx, bool to_segfault) {
+
+#if HOST_CPU == CPU_ARM
+	swap(reictx->pc, MCTX(arm_pc), to_segfault);
+#elif HOST_CPU == CPU_X86
+	swap(reictx->pc, MCTX(gregs[REG_EIP]), to_segfault);
+	swap(reictx->esp, MCTX(gregs[REG_ESP]), to_segfault);
+	swap(reictx->eax, MCTX(gregs[REG_EAX]), to_segfault);
+	swap(reictx->ecx, MCTX(gregs[REG_ECX]), to_segfault);
+#elif HOST_CPU == CPU_MIPS
+	swap(reictx->pc, MCTX(pc), to_segfault);
+#else
+#error Unsupported HOST_CPU
+#endif
+	
+}
+
+void context_from_segfault(rei_host_context_t* reictx, void* segfault_ctx) {
+	context_segfault(reictx, segfault_ctx, false);
+}
+
+void context_to_segfault(rei_host_context_t* reictx, void* segfault_ctx) {
+	context_segfault(reictx, segfault_ctx, true);
+}

core/linux/context.h

@@ -0,0 +1,17 @@
+#include "types.h"
+
+
+struct rei_host_context_t {
+	unat pc;
+
+#if HOST_CPU == CPU_X86
+	u32 eax;
+	u32 ecx;
+	u32 esp;
+#elif HOST_CPU == CPU_ARM
+	u32 r0;
+#endif
+};
+
+void context_from_segfault(rei_host_context_t* reictx, void* segfault_ctx);
+void context_to_segfault(rei_host_context_t* reictx, void* segfault_ctx);