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applyGsDispEnv programs display read circuit 2 only #152

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6978322
fix(runtime): program display read circuit 2 only in applyGsDispEnv a…
smmathews Jul 7, 2026
658322f
Merge remote-tracking branch 'origin/main' into wf-pr152
smmathews Jul 15, 2026
592aaf6
fix(recomp): include <cstdint> before elfio.hpp for fixed-width int t…
smmathews Jul 15, 2026
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1 change: 1 addition & 0 deletions ps2xRecomp/include/ps2recomp/elf_parser.h
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
#ifndef PS2RECOMP_ELF_PARSER_H
#define PS2RECOMP_ELF_PARSER_H

#include <cstdint>
#include <elfio/elfio.hpp>
#include <string>
#include <vector>
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8 changes: 6 additions & 2 deletions ps2xRuntime/src/lib/Kernel/Stubs/GS.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1053,7 +1053,9 @@ namespace ps2_stubs
}

const uint32_t fbw = std::max<uint32_t>(1u, (w + 63u) / 64u);
const uint64_t pmode = makePmode(1u, 1u, 0u, 0u, 0u, 0x80u);
// Seed read circuit 2 only (EN2): the swap path programs DISPFB2/DISPLAY2 and
// never circuit 1, so enabling EN1 would advertise a circuit it never drives.
const uint64_t pmode = makePmode(0u, 1u, 0u, 0u, 0u, 0x80u);
const uint64_t smode2 =
(static_cast<uint64_t>(g_gparam.interlace & 0x1u) << 0) |
(static_cast<uint64_t>(g_gparam.ffmode & 0x1u) << 1);
Expand Down Expand Up @@ -1124,7 +1126,9 @@ namespace ps2_stubs
}

const uint32_t fbw = std::max<uint32_t>(1u, (w + 63u) / 64u);
const uint64_t pmode = makePmode(1u, 1u, 0u, 0u, 0u, 0x80u);
// Seed read circuit 2 only (EN2): the swap path programs DISPFB2/DISPLAY2 and
// never circuit 1, so enabling EN1 would advertise a circuit it never drives.
const uint64_t pmode = makePmode(0u, 1u, 0u, 0u, 0u, 0x80u);
const uint64_t smode2 =
(static_cast<uint64_t>(g_gparam.interlace & 0x1u) << 0) |
(static_cast<uint64_t>(g_gparam.ffmode & 0x1u) << 1);
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5 changes: 3 additions & 2 deletions ps2xRuntime/src/lib/Kernel/Stubs/Helpers/Support.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1883,8 +1883,9 @@ namespace
auto &regs = runtime->memory().gs();
regs.pmode = env.pmode;
regs.smode2 = env.smode2;
regs.dispfb1 = env.dispfb;
regs.display1 = env.display;
// Circuit 1 (DISPFB1/DISPLAY1) is deliberately not programmed: the env
// describes read circuit 2 only, and the game drives circuit 1 itself via
// GS MMIO. Writing it here would collapse any two-buffer blend.
regs.dispfb2 = env.dispfb;
regs.display2 = env.display;
regs.bgcolor = env.bgcolor;
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147 changes: 145 additions & 2 deletions ps2xTest/src/ps2_gs_tests.cpp
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Expand Up @@ -466,12 +466,155 @@ void register_ps2_gs_tests()
setRegU32(ctx, 5, 1u);
ps2_stubs::sceGsSwapDBuffDc(rdram.data(), &ctx, &runtime);

t.Equals(runtime.memory().gs().dispfb1 & 0x1FFull, 151ull,
t.Equals(runtime.memory().gs().dispfb2 & 0x1FFull, 151ull,
"sceGsSwapDBuffDc should program GS to the selected display page");
t.Equals((runtime.memory().gs().display1 >> 32) & 0x0FFFull, 639ull,
t.Equals((runtime.memory().gs().display2 >> 32) & 0x0FFFull, 639ull,
"sceGsSwapDBuffDc should preserve the display width from the seeded env");
});

tc.Run("sceGsSwapDBuffDc drives read circuit 2 only and preserves circuit 1", [](TestCase &t)
{
PS2Runtime runtime;
t.IsTrue(runtime.memory().initialize(), "runtime memory initialize should succeed");

// Seed distinct circuit-1 sentinels AFTER initialize(); reset
// defaults are fbw=10 / 639x447, so these differ from them.
runtime.memory().gs().dispfb1 = 0xDEADBEEFDEADBEEFull;
runtime.memory().gs().display1 = 0xCAFEF00DCAFEF00Dull;
runtime.memory().gs().pmode = 0u;

std::vector<uint8_t> rdram(PS2_RAM_SIZE, 0u);
constexpr uint32_t kEnvAddr = 0x7000u;
constexpr uint32_t kDBuffSize = 0x330u;

R5900Context ctx{};
setRegU32(ctx, 4, kEnvAddr);
setRegU32(ctx, 5, 0u); // psm
setRegU32(ctx, 6, 640u); // width
setRegU32(ctx, 7, 448u); // height
std::memset(rdram.data() + kEnvAddr, 0xCD, kDBuffSize);
ps2_stubs::sceGsSetDefDBuffDc(rdram.data(), &ctx, &runtime);

std::memset(&ctx, 0, sizeof(ctx));
setRegU32(ctx, 4, kEnvAddr);
setRegU32(ctx, 5, 1u); // swap to page 1
ps2_stubs::sceGsSwapDBuffDc(rdram.data(), &ctx, &runtime);

// Double-buffer path is circuit-2-only: the seeded PMODE must not enable
// EN1, or the compositor blends a never-programmed circuit-1 surface.
t.Equals(runtime.memory().gs().pmode & 0x1ull, 0x0ull,
"sceGsSwapDBuffDc must not enable read circuit 1 (EN1) in PMODE");
t.Equals(runtime.memory().gs().pmode & 0x2ull, 0x2ull,
"sceGsSwapDBuffDc should enable read circuit 2 (EN2) in PMODE");

// The shared circuit-2-only helper must leave circuit 1 untouched.
t.Equals(runtime.memory().gs().dispfb1, 0xDEADBEEFDEADBEEFull,
"sceGsSwapDBuffDc must not clobber circuit-1 DISPFB1");
t.Equals(runtime.memory().gs().display1, 0xCAFEF00DCAFEF00Dull,
"sceGsSwapDBuffDc must not clobber circuit-1 DISPLAY1");
});

tc.Run("sceGsSwapDBuff drives read circuit 2 only and preserves circuit 1", [](TestCase &t)
{
PS2Runtime runtime;
t.IsTrue(runtime.memory().initialize(), "runtime memory initialize should succeed");

// Seed distinct circuit-1 sentinels AFTER initialize(); reset
// defaults are fbw=10 / 639x447, so these differ from them.
runtime.memory().gs().dispfb1 = 0xDEADBEEFDEADBEEFull;
runtime.memory().gs().display1 = 0xCAFEF00DCAFEF00Dull;
runtime.memory().gs().pmode = 0u;

std::vector<uint8_t> rdram(PS2_RAM_SIZE, 0u);
constexpr uint32_t kEnvAddr = 0x8000u;
constexpr uint32_t kDBuffSize = 0x330u;
constexpr uint32_t kStackAddr = 0xB00u;

R5900Context ctx{};
setRegU32(ctx, 4, kEnvAddr);
setRegU32(ctx, 5, 0u); // psm
setRegU32(ctx, 6, 640u); // width
setRegU32(ctx, 7, 448u); // height
// sceGsSetDefDBuff (non-Dc) reads its trailing ztest/zpsm/clear
// args from the guest stack via sp+16/sp+20/sp+24, so sp (r29)
// must point at valid, zero-initialized rdram.
setRegU32(ctx, 29, kStackAddr);
std::memset(rdram.data() + kEnvAddr, 0xCD, kDBuffSize);
ps2_stubs::sceGsSetDefDBuff(rdram.data(), &ctx, &runtime);

std::memset(&ctx, 0, sizeof(ctx));
setRegU32(ctx, 4, kEnvAddr);
setRegU32(ctx, 5, 1u); // swap to page 1
ps2_stubs::sceGsSwapDBuff(rdram.data(), &ctx, &runtime);

// Double-buffer path is circuit-2-only: the seeded PMODE must not enable
// EN1, or the compositor blends a never-programmed circuit-1 surface.
t.Equals(runtime.memory().gs().pmode & 0x1ull, 0x0ull,
"sceGsSwapDBuff must not enable read circuit 1 (EN1) in PMODE");
t.Equals(runtime.memory().gs().pmode & 0x2ull, 0x2ull,
"sceGsSwapDBuff should enable read circuit 2 (EN2) in PMODE");

// The shared circuit-2-only helper must leave circuit 1 untouched.
t.Equals(runtime.memory().gs().dispfb1, 0xDEADBEEFDEADBEEFull,
"sceGsSwapDBuff must not clobber circuit-1 DISPFB1");
t.Equals(runtime.memory().gs().display1, 0xCAFEF00DCAFEF00Dull,
"sceGsSwapDBuff must not clobber circuit-1 DISPLAY1");
});

tc.Run("sceGsPutDispEnv programs read circuit 2 only and leaves circuit 1 untouched", [](TestCase &t)
{
PS2Runtime runtime;
t.IsTrue(runtime.memory().initialize(), "runtime memory initialize should succeed");

runtime.memory().gs().dispfb1 = 0xDEADBEEFDEADBEEFull;
runtime.memory().gs().display1 = 0xCAFEF00DCAFEF00Dull;
runtime.memory().gs().dispfb2 = 0u;
runtime.memory().gs().display2 = 0u;
runtime.memory().gs().pmode = 0u;
runtime.memory().gs().smode2 = 0u;
runtime.memory().gs().bgcolor = 0u;

std::vector<uint8_t> rdram(PS2_RAM_SIZE, 0u);
constexpr uint32_t kEnvAddr = 0x6000u;
constexpr uint32_t kPmodeOffset = 0u;
constexpr uint32_t kSmode2Offset = 8u;
constexpr uint32_t kDispFbOffset = 16u;
constexpr uint32_t kDisplayOffset = 24u;
constexpr uint32_t kBgColorOffset = 32u;

const uint64_t pmode = 0x8007ull;
const uint64_t smode2 = 0x1ull;
const uint64_t dispfb = 0x9070ull;
const uint64_t display = 0x1234000000005678ull;
const uint64_t bgcolor = 0x00445566ull;

std::memcpy(rdram.data() + kEnvAddr + kPmodeOffset, &pmode, sizeof(pmode));
std::memcpy(rdram.data() + kEnvAddr + kSmode2Offset, &smode2, sizeof(smode2));
std::memcpy(rdram.data() + kEnvAddr + kDispFbOffset, &dispfb, sizeof(dispfb));
std::memcpy(rdram.data() + kEnvAddr + kDisplayOffset, &display, sizeof(display));
std::memcpy(rdram.data() + kEnvAddr + kBgColorOffset, &bgcolor, sizeof(bgcolor));

R5900Context ctx{};
setRegU32(ctx, 4, kEnvAddr);
ps2_stubs::sceGsPutDispEnv(rdram.data(), &ctx, &runtime);

t.Equals(runtime.memory().gs().pmode, pmode,
"sceGsPutDispEnv should program PMODE from the env");
t.Equals(runtime.memory().gs().smode2, smode2,
"sceGsPutDispEnv should program SMODE2 from the env");
t.Equals(runtime.memory().gs().dispfb2, dispfb,
"sceGsPutDispEnv should program DISPFB2 from the env");
t.Equals(runtime.memory().gs().display2, display,
"sceGsPutDispEnv should program DISPLAY2 from the env");
t.Equals(runtime.memory().gs().bgcolor, bgcolor,
"sceGsPutDispEnv should program BGCOLOR from the env");

t.Equals(runtime.memory().gs().dispfb1, 0xDEADBEEFDEADBEEFull,
"sceGsPutDispEnv must not clobber circuit-1 DISPFB1");
t.Equals(runtime.memory().gs().display1, 0xCAFEF00DCAFEF00Dull,
"sceGsPutDispEnv must not clobber circuit-1 DISPLAY1");
});

tc.Run("sceGsSetDefDBuffDc seeds a clear packet and swap clears the draw buffer", [](TestCase &t)
{
PS2Runtime runtime;
Expand Down