From 1c620dafbc965336c5678b24cb691a4aefb97ebb Mon Sep 17 00:00:00 2001
From: Stephen Miller <56742918+StevenMiller123@users.noreply.github.com>
Date: Thu, 12 Feb 2026 15:09:55 -0600
Subject: [PATCH] Mount system fonts

Now that font LLE works, these are necessary for some titles.
---
 src/common/path_util.cpp           |  1 +
 src/common/path_util.h             |  2 ++
 src/core/libraries/kernel/kernel.h |  1 +
 src/emulator.cpp                   | 29 +++++++++++++++++++++++++++++
 4 files changed, 33 insertions(+)

diff --git a/src/common/path_util.cpp b/src/common/path_util.cpp
index b0cbb10cf..5d37990ff 100644
--- a/src/common/path_util.cpp
+++ b/src/common/path_util.cpp
@@ -128,6 +128,7 @@ static auto UserPaths = [] {
     create_path(PathType::CustomTrophy, user_dir / CUSTOM_TROPHY);
     create_path(PathType::CustomConfigs, user_dir / CUSTOM_CONFIGS);
     create_path(PathType::CacheDir, user_dir / CACHE_DIR);
+    create_path(PathType::FontsDir, user_dir / FONTS_DIR);
 
     std::ofstream notice_file(user_dir / CUSTOM_TROPHY / "Notice.txt");
     if (notice_file.is_open()) {
diff --git a/src/common/path_util.h b/src/common/path_util.h
index fd2c18baa..434f77b0d 100644
--- a/src/common/path_util.h
+++ b/src/common/path_util.h
@@ -25,6 +25,7 @@ enum class PathType {
     CustomTrophy,   // Where custom files for trophies are stored.
     CustomConfigs,  // Where custom files for different games are stored.
     CacheDir,       // Where pipeline and shader cache is stored.
+    FontsDir,       // Where dumped system fonts are stored.
 };
 
 constexpr auto PORTABLE_DIR = "user";
@@ -44,6 +45,7 @@ constexpr auto METADATA_DIR = "game_data";
 constexpr auto CUSTOM_TROPHY = "custom_trophy";
 constexpr auto CUSTOM_CONFIGS = "custom_configs";
 constexpr auto CACHE_DIR = "cache";
+constexpr auto FONTS_DIR = "fonts";
 
 // Filenames
 constexpr auto LOG_FILE = "shad_log.txt";
diff --git a/src/core/libraries/kernel/kernel.h b/src/core/libraries/kernel/kernel.h
index 91fac4c71..ce6446129 100644
--- a/src/core/libraries/kernel/kernel.h
+++ b/src/core/libraries/kernel/kernel.h
@@ -17,6 +17,7 @@ void ErrSceToPosix(s32 result);
 s32 ErrnoToSceKernelError(s32 e);
 void SetPosixErrno(s32 e);
 s32* PS4_SYSV_ABI __Error();
+const char* PS4_SYSV_ABI sceKernelGetFsSandboxRandomWord();
 
 extern Core::EntryParams entry_params;
 
diff --git a/src/emulator.cpp b/src/emulator.cpp
index 0dde0b7fa..4a1473abe 100644
--- a/src/emulator.cpp
+++ b/src/emulator.cpp
@@ -36,6 +36,7 @@
 #include "core/libraries/font/font.h"
 #include "core/libraries/font/fontft.h"
 #include "core/libraries/jpeg/jpegenc.h"
+#include "core/libraries/kernel/kernel.h"
 #include "core/libraries/libc_internal/libc_internal.h"
 #include "core/libraries/libpng/pngenc.h"
 #include "core/libraries/libs.h"
@@ -368,6 +369,34 @@ void Emulator::Run(std::filesystem::path file, std::vector<std::string> args,
     }
     VideoCore::SetOutputDir(mount_captures_dir, id);
 
+    // Mount system fonts
+    const auto& fonts_dir = Common::FS::GetUserPath(Common::FS::PathType::FontsDir);
+    if (!std::filesystem::exists(fonts_dir)) {
+        std::filesystem::create_directory(fonts_dir);
+    }
+
+    // Fonts are mounted into the sandboxed system directory, construct the appropriate path.
+    const char* sandbox_root = Libraries::Kernel::sceKernelGetFsSandboxRandomWord();
+    std::string guest_font_dir = "/";
+    guest_font_dir.append(sandbox_root).append("/common/font");
+    const auto& host_font_dir = fonts_dir / "font";
+    if (!std::filesystem::exists(host_font_dir)) {
+        std::filesystem::create_directory(host_font_dir);
+    }
+    mnt->Mount(host_font_dir, guest_font_dir);
+
+    // There is a second font directory, mount that too.
+    guest_font_dir.append("2");
+    const auto& host_font2_dir = fonts_dir / "font2";
+    if (!std::filesystem::exists(host_font2_dir)) {
+        std::filesystem::create_directory(host_font2_dir);
+    }
+    mnt->Mount(host_font2_dir, guest_font_dir);
+
+    if (std::filesystem::is_empty(host_font_dir) || std::filesystem::is_empty(host_font2_dir)) {
+        LOG_WARNING(Loader, "No dumped system fonts, expect missing text or instability");
+    }
+
     // Initialize kernel and library facilities.
     Libraries::InitHLELibs(&linker->GetHLESymbols());