[nostalgia] Integrate Ox Preloader

src/nostalgia/core/gba/core.cpp

@@ -37,13 +37,31 @@ static void initTimer() noexcept {
 	REG_IE = REG_IE | Int_timer0;
 }
 
+static ox::Result<std::size_t> findPreloadSection() noexcept {
+	// put the header in the wrong order to prevent mistaking this code for the
+	// media section
+	constexpr auto headerP2 = "D_HEADER________";
+	constexpr auto headerP1 = "NOSTALGIA_PRELOA";
+	constexpr auto headerP1Len = ox_strlen(headerP2);
+	constexpr auto headerP2Len = ox_strlen(headerP1);
+	constexpr auto headerLen = headerP1Len + headerP2Len;
+	for (auto current = MEM_ROM; current < reinterpret_cast<char*>(0x0a000000); current += headerLen) {
+		if (ox_memcmp(current, headerP1, headerP1Len) == 0 &&
+		    ox_memcmp(current + headerP1Len, headerP2, headerP2Len) == 0) {
+			return reinterpret_cast<std::size_t>(current + headerLen);
+		}
+	}
+	return OxError(1);
+}
+
 ox::Result<ox::UniquePtr<Context>> init(ox::UniquePtr<ox::FileSystem> fs, const char *appName) noexcept {
 	auto ctx = ox::make_unique<Context>();
 	ctx->rom = std::move(fs);
-	ctx->appName = std::move(appName);
+	ctx->appName = appName;
 	oxReturnError(initGfx(ctx.get()));
 	initTimer();
 	initIrq();
+	oxReturnError(findPreloadSection().moveTo(&ctx->preloadSectionOffset));
 	return ctx;
 }
 

src/nostalgia/core/gba/gfx.cpp

@@ -213,7 +213,8 @@ ox::Error loadSpritePalette(Context *ctx, unsigned cbb, const ox::FileAddress &p
 // Do NOT use Context in the GBA version of this function.
 void puts(Context *ctx, int column, int row, const char *str) noexcept {
 	for (int i = 0; str[i]; i++) {
-		setTile(ctx, 0, column + i, row, static_cast<uint8_t>(charMap[static_cast<int>(str[i])]));
+		const auto c = charMap[static_cast<unsigned>(str[i])];
+		setTile(ctx, 0, column + i, row, static_cast<uint8_t>(c));
 	}
 }
 

src/nostalgia/core/gba/media.cpp

@@ -2,7 +2,8 @@
  * Copyright 2016 - 2022 Gary Talent (gary@drinkingtea.net). All rights reserved.
  */
 
-#include <ox/fs/fs.hpp>
+#include <ox/mc/read.hpp>
+#include <ox/preloader/preloader.hpp>
 #include <ox/std/std.hpp>
 
 #include "../media.hpp"
@@ -14,11 +15,11 @@ namespace nostalgia::core {
 ox::Result<char*> loadRom(const char*) noexcept {
 	// put the header in the wrong order to prevent mistaking this code for the
 	// media section
-	constexpr auto headerP2 = "_HEADER_________";
-	constexpr auto headerP1 = "NOSTALGIA_MEDIA";
-	constexpr auto headerP1Len = 15;
-	constexpr auto headerP2Len = 16;
-	constexpr auto headerLen = headerP1Len + headerP2Len + 1;
+	constexpr auto headerP2 = "HEADER__________";
+	constexpr auto headerP1 = "NOSTALGIA_MEDIA_";
+	constexpr auto headerP1Len = ox_strlen(headerP2);
+	constexpr auto headerP2Len = ox_strlen(headerP1);
+	constexpr auto headerLen = headerP1Len + headerP2Len;
 	for (auto current = MEM_ROM; current < reinterpret_cast<char*>(0x0a000000); current += headerLen) {
 		if (ox_memcmp(current, headerP1, headerP1Len) == 0 &&
 		    ox_memcmp(current + headerP1Len, headerP2, headerP2Len) == 0) {
@@ -31,4 +32,12 @@ ox::Result<char*> loadRom(const char*) noexcept {
 void unloadRom(char*) noexcept {
 }
 
+ox::Result<std::size_t> getPreloadAddr(Context *ctx, const ox::FileAddress &file) noexcept {
+	oxRequire(stat, ctx->rom->stat(file));
+	oxRequire(buff, ctx->rom->directAccess(file));
+	PreloadPtr p;
+	oxReturnError(ox::readMC(buff, stat.size, &p));
+	return p.preloadAddr + ctx->preloadSectionOffset;
+}
+
 }