New debugging primitive: break whenever any instruction writes to a
given general-purpose register (0-31), regardless of which address
executes the write. Requested for continuing the reboot.bin trace,
where the actual blocker is "what sets $s3 to this bad value", not
"what happens at a specific address" - existing address/memory
breakpoints can't express that directly.
- GPRBreakpoint (Core/Debugger/Breakpoints.h) mirrors the existing
BreakPoint/MemCheck shape (result/condition/logFormat/hit count),
keyed by register index instead of address/range.
- BreakpointManager keeps a u32 bitmask (bit i = register i has an
active breakpoint) alongside the GPRBreakpoint vector, so the
interpreter loop can test "would this write trip anything" with a
single shift+and against a value already cached in a local.
- RunUntilDowncountZeroWithChecks (Core/MIPS/MIPSTables.cpp) computes
the about-to-be-written register from the current instruction's
OUT_RT/OUT_RD/OUT_RA flags (GetGPRWriteTarget()) and checks it
against the mask, same convention as the existing memcheck handling
right above it (checked before the instruction executes, bails via
CORE_STEPPING_CPU without running it if tripped).
- New BreakReason::GPRBreakpoint ("cpu.gprBreakpoint") for Core_Break.
- WebSocket API: cpu.gprBreakpoint.add/update/remove/list, accepting
either a 0-31 'register' index or a case-insensitive 'name' (e.g.
"s3"), documented in docs/WebSocketDebugger.md.
Interpreter-only for now, deliberately.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZq8ZtJmFY7bkX5FVkr3P9
Core_RunLoopUntil() is only reached while a game is actually loaded and
running (via EmuScreen). Anything calling Core_RunOnCPUThread() while at
the main menu with no game loaded would hang forever waiting for a queue
that was never drained. Call Core_ProcessCPUQueue() directly from
NativeFrame(), just before screenManager->render(), so it always runs;
Core_RunLoopUntil() still also drains it for the tight-spin-while-stepping
case once a game is running.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm11k99viLfbJm2MkH4BH
Debugger windows (register list, disassembly view, memory view, breakpoint/
thread/module/stack lists, watch list) read CPU-thread-owned state directly
from the GUI thread's WM_PAINT/list-fill handlers, racing against the CPU
thread. Routing every read through Core_RunOnCPUThread would be too slow for
something invoked continuously on paint/list-refresh.
Add g_frameMutex (Core.h/Core.cpp), held by NativeFrame() only across the
span where it actually touches that state (running the CPU, processing
breakpoints, running the ImGui debugger) - not across input handling or the
present/frame-pacing waits. Debugger windows now hold the same mutex while
reading, giving synchronized reads without the round-trip cost of queuing
to the CPU thread.
CtrlRegisterList::onPaint() goes back to always reading live values (now
safe under the lock) and grays them out by color alone while the core is
running, rather than the earlier snapshot-caching approach.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm11k99viLfbJm2MkH4BH
The WebSocket debugger's cpu.stepInto handler ran entirely on the WebSocket
handler thread, directly manipulating breakpoints and stepping state (via
Core_RequestCPUStep, g_breakpoints.SetSkipFirst, etc.) that's otherwise only
ever touched from the CPU thread (the one that calls Core_RunLoopUntil, and
thus indirectly NativeFrame).
Adds Core_RunOnCPUThread() - queues a function to run on the CPU thread and
blocks the caller until it's done. The queue is drained at the top of
Core_RunLoopUntil()'s loop, so it's reached continuously (in a tight spin)
while the CPU is stepping/paused, and at least once per call even while fully
running.
cpu.stepInto is the first consumer: once the CPU is already stepping, the
breakpoint/stepping manipulation is now routed through Core_RunOnCPUThread
instead of happening directly on the WebSocket thread. The "not currently
stepping" path still calls Core_Break() directly from the WebSocket thread,
since it's already documented free-threaded and is what makes the CPU thread
start reaching the queue-drain point in the first place.
More WebSocket debugger commands can be converted the same way going forward.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm11k99viLfbJm2MkH4BH
DisassemblyManager used to fuse lui+addiu/load/store into single pseudo-
instructions ("li", fused loads/stores) for display. This only applied to a
handful of opcodes, complicated DisassemblyManager, and was the root cause of
a stepping bug: Core_PerformCPUStep's Into/Over cases treated stepSize as a
byte count, while the WebSocket cpu.stepInto handler computed it as an
instruction count (needed to step over a whole fused macro in one go) - so a
plain, non-fused stepInto silently executed zero instructions.
Removed the fusion logic entirely (DisassemblyMacro, DISTYPE_MACRO) - every
disassembly line is now exactly one 4-byte instruction. With that,
"how many instructions does this line span" is always 1, so the
getInstructionSizeAt() byte-size queries in the legacy Windows and ImGui
debuggers are gone too; step requests just pass 1. Core_RequestCPUStep's
stepSize is now consistently in instructions everywhere.
Also fixes the PPSSPPHeadless build, broken since 0ed1f3e added
OpenWebDebugger() (which calls System_LaunchUrl) without a headless stub.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Hqm11k99viLfbJm2MkH4BH
Added KernelModuleAddressDescription() (Core/HLE/sceKernelModule.cpp),
which looks up which currently loaded module (and text/data/bss/segment
section within it) an address falls in, e.g. "EBOOT.BIN.text+1234".
Wired it into:
- Core_MemoryException/Core_ExecException/Core_BreakException
(Core/Core.cpp), appended next to every address/pc/ra shown in their
log lines.
- FormatStackTrace (Core/MemFault.cpp), appended per-frame next to the
existing symbol description.
This makes crash/exception logs actionable even when there's no symbol
at the faulting address - you at least get which module and section
it's in, useful for reverse engineering unfamiliar code.
Verified live via headless: injected a MIPS break instruction at the
current PC (through Tools/wsdbg) and confirmed the log line changed from
"break instruction hit at 088040ac" to "break instruction hit at 088040ac
[sceDisplayWaitVblank Test.text+ac]".
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XDNwPPuidmNxQGRJxBuRL6
