Improve signal handling and math

- Polyfill ucontext_t on FreeBSD/OpenBSD/NetBSD
- Add tests confirming signals can edit CPU state
- Work towards supporting ZIP filesystem on bare metal
- Add more tinymath unit tests for POSIX conformance
- Add X87 and SSE status flags to crash report
- Fix some bugs in blinkenlights
- Fix llvm build breakage

libc/runtime/abort-nt.c

@@ -24,9 +24,13 @@
 #include "libc/sysv/consts/sig.h"
 
 textwindows wontreturn void sys_abort_nt(void) {
+  int rva;
   siginfo_t info;
   memset(&info, 0, sizeof(info));
   info.si_signo = SIGABRT;
-  __sigenter(SIGABRT, &info, NULL);
+  rva = __sighandrvas[SIGABRT];
+  if (rva >= kSigactionMinRva) {
+    ((sigaction_f)(_base + rva))(SIGABRT, &info, NULL);
+  }
   _Exit(128 + SIGABRT);
 }

libc/runtime/efimain.greg.c

@@ -81,7 +81,7 @@ __msabi noasan EFI_STATUS EfiMain(EFI_HANDLE ImageHandle,
    * Allocates and clears PC-compatible memory and copies image.
    */
   SystemTable->BootServices->AllocatePages(
-      EfiConventionalMemory, AllocateAddress,
+      AllocateAddress, EfiConventionalMemory,
       MAX(2 * 1024 * 1024, 1024 * 1024 + (_end - _base)) / 4096, 0);
   SystemTable->BootServices->SetMem(0, 0x80000, 0);
   SystemTable->BootServices->CopyMem((void *)(1024 * 1024), _base,

libc/runtime/g_argc.S

@@ -19,13 +19,13 @@
 #include "libc/macros.h"
 #include "libc/notice.inc"
 
-	.initbss 300,_init___argc
-/	Global variable holding _start(argc) parameter.
+	.initbss 300,_init_argc
+//	Global variable holding _start(argc) parameter.
 __argc:	.quad	0
 	.endobj	__argc,globl
 	.previous
 
-	.init.start 300,_init___argc
+	.init.start 300,_init_argc
 	mov	%r12,%rax
 	stosq
-	.init.end 300,_init___argc
+	.init.end 300,_init_argc

libc/runtime/pc.internal.h

@@ -58,8 +58,12 @@
    B: FPU Busy ───────────┐│ │  │ ││││││││
                           ││┌┴┐┌┼┐││││││││
                           │↓│ │↓↓↓││││││││*/
-#define FPU_IE 0b0000000000100000000000001
-#define FPU_ZE 0b0000000000100000000000100
+#define FPU_IE 0b0000000000000000000000001
+#define FPU_DE 0b0000000000000000000000010
+#define FPU_ZE 0b0000000000000000000000100
+#define FPU_OE 0b0000000000000000000001000
+#define FPU_UE 0b0000000000000000000010000
+#define FPU_PE 0b0000000000000000000100000
 #define FPU_SF 0b0000000000000000001000000
 #define FPU_C0 0b0000000000000000100000000
 #define FPU_C1 0b0000000000000001000000000

libc/runtime/winmain.greg.c

@@ -66,7 +66,20 @@ static noasan textwindows void SetTrueColor(void) {
 }
 
 static noasan textwindows void MakeLongDoubleLongAgain(void) {
-  int x87cw = 0x037f; /* let's hope win32 won't undo this */
+  /* 8087 FPU Control Word
+      IM: Invalid Operation ───────────────┐
+      DM: Denormal Operand ───────────────┐│
+      ZM: Zero Divide ───────────────────┐││
+      OM: Overflow ─────────────────────┐│││
+      UM: Underflow ───────────────────┐││││
+      PM: Precision ──────────────────┐│││││
+     PC: Precision Control ────────┐  ││││││
+      {float,∅,double,long double} │  ││││││
+     RC: Rounding Control ───────┐ │  ││││││
+      {even, →-∞, →+∞, →0}       │┌┤  ││││││
+                                ┌┤││  ││││││
+                               d││││rr││││││*/
+  int x87cw = 0b0000000000000000001101111111;
   asm volatile("fldcw\t%0" : /* no outputs */ : "m"(x87cw));
 }