ectx: add ectxrPullContext (#511)

nx/include/switch.h

@@ -123,6 +123,7 @@ extern "C" {
 #include "switch/services/lp2p.h"
 #include "switch/services/news.h"
 #include "switch/services/ins.h"
+#include "switch/services/ectx.h"
 
 #include "switch/display/binder.h"
 #include "switch/display/parcel.h"

nx/include/switch/services/ectx.h

@@ -0,0 +1,32 @@
+/**
+ * @file ectx.h
+ * @brief [11.0.0+] Error Context services IPC wrapper.
+ * @author SciresM
+ * @copyright libnx Authors
+ */
+#pragma once
+#include "../types.h"
+#include "../kernel/event.h"
+#include "../sf/service.h"
+
+/// Initialize ectx:r.
+Result ectxrInitialize(void);
+
+/// Exit ectx:r.
+void ectxrExit(void);
+
+/// Gets the Service object for the actual ectx:r service session.
+Service* ectxrGetServiceSession(void);
+
+/**
+ * @brief Retrieves the error context associated with an error descriptor and result.
+ * @param[out] out0 Output value.
+ * @param[out] out_total_size Total error context size.
+ * @param[out] out_size Error context size.
+ * @param[out] dst Buffer for output error context.
+ * @param[in] dst_size Buffer size for output error context.
+ * @param[in] descriptor Error descriptor.
+ * @param[in] result Error result.
+ * @return Result code.
+ */
+Result ectxrPullContext(s32 *out0, u32 *out_total_size, u32 *out_size, void *dst, size_t dst_size, u32 descriptor, Result result);

nx/source/services/ectx.c

@@ -0,0 +1,48 @@
+#define NX_SERVICE_ASSUME_NON_DOMAIN
+#include "service_guard.h"
+#include "runtime/hosversion.h"
+#include "services/ectx.h"
+
+static Service g_ectxrSrv;
+
+NX_GENERATE_SERVICE_GUARD(ectxr);
+
+Result _ectxrInitialize(void) {
+    if (hosversionBefore(11,0,0))
+        return MAKERESULT(Module_Libnx, LibnxError_IncompatSysVer);
+    return smGetService(&g_ectxrSrv, "ectx:r");
+}
+
+void _ectxrCleanup(void) {
+    serviceClose(&g_ectxrSrv);
+}
+
+Service* ectxrGetServiceSession(void) {
+    return &g_ectxrSrv;
+}
+
+Result ectxrPullContext(s32 *out0, u32 *out_total_size, u32 *out_size, void *dst, size_t dst_size, u32 descriptor, Result result) {
+    const struct {
+        u32 desc;
+        u32 res;
+    } in = { descriptor, result };
+
+    struct {
+        s32 unk0;
+        u32 total_size;
+        u32 size;
+    } out;
+
+    Result rc = serviceDispatchInOut(&g_ectxrSrv, 1, in, out,
+        .buffer_attrs = { SfBufferAttr_HipcMapAlias | SfBufferAttr_Out },
+        .buffers = { { dst, dst_size } },
+    );
+
+    if (R_SUCCEEDED(rc)) {
+        if (out0) *out0 = out.unk0;
+        if (out_total_size) *out_total_size = out.total_size;
+        if (out_size) *out_size = out.size;
+    }
+
+    return rc;
+}