More NCSD loading

src/core/loader/ncsd.cpp

@@ -0,0 +1,68 @@
+#include <optional>
+#include "loader/ncsd.hpp"
+#include "memory.hpp"
+
+std::optional<NCSD> Memory::loadNCSD(const std::filesystem::path& path) {
+    NCSD ncsd;
+    if (!ncsd.file.open(path, "rb"))
+        return std::nullopt;
+
+    u8 magic[4]; // Must be "NCSD"
+    ncsd.file.seek(0x100);
+    auto [success, bytes] = ncsd.file.readBytes(magic, 4);
+
+    if (!success || bytes != 4) {
+        printf("Failed to read NCSD magic\n");
+        return std::nullopt;
+    }
+
+    if (magic[0] != 'N' || magic[1] != 'C' || magic[2] != 'S' || magic[3] != 'D') {
+        printf("NCSD with wrong magic value\n");
+        return std::nullopt;
+    }
+
+    std::tie(success, bytes) = ncsd.file.readBytes(&ncsd.size, 4);
+    if (!success || bytes != 4) {
+        printf("Failed to read NCSD size\n");
+        return std::nullopt;
+    }
+
+    ncsd.size *= NCSD::mediaUnit; // Convert size to bytes
+
+    // Read partition data
+    ncsd.file.seek(0x120);
+    // 2 u32s per partition (offset and length), 8 partitions total
+    constexpr size_t partitionDataSize = 8 * 2; // Size of partition in u32s
+    u32 partitionData[8 * 2];
+    std::tie(success, bytes) = ncsd.file.read(partitionData, partitionDataSize, sizeof(u32));
+    if (!success || bytes != partitionDataSize) {
+        printf("Failed to read NCSD partition data\n");
+        return std::nullopt;
+    }
+
+    for (int i = 0; i < 8; i++) {
+        auto& partition = ncsd.partitions[i];
+        partition.offset = u64(partitionData[i * 2]) * NCSD::mediaUnit;
+        partition.length = u64(partitionData[i * 2 + 1]) * NCSD::mediaUnit;
+
+        if (partition.length != 0) { // Initialize the NCCH of each partition
+            ncsd.file.seek(partition.offset);
+
+            // 0x200 bytes for the NCCH header and another 0x800 for the exheader
+            constexpr u64 headerSize = 0x200 + 0x800;
+            u8 ncchHeader[headerSize];
+            std::tie(success, bytes) = ncsd.file.readBytes(ncchHeader, headerSize);
+            if (!success || bytes != headerSize) {
+                printf("Failed to read NCCH header\n");
+                return std::nullopt;
+            }
+
+            if (!partition.ncch.loadFromHeader(ncchHeader)) {
+                printf("Invalid NCCH partition\n");
+                return std::nullopt;
+            }
+        }
+    }
+
+    return ncsd;
+}