[metal] Locate some ACPI tables, for later hardware detection

Specifically the code now tries to find the ACPI RSDP,
RSDT/XSDT, FADT, & MADT tables, whether in legacy BIOS
bootup mode or in a UEFI bootup.  These are useful for
figuring out how to (re)enable asynchronous interrupts
in legacy 8259 PIC mode.

Makefile

@@ -136,11 +136,13 @@ include third_party/puff/puff.mk		# │
 include libc/elf/elf.mk				# │
 include ape/ape.mk				# │
 include libc/fmt/fmt.mk				# │
-include libc/vga/vga.mk				#─┘
+include libc/vga/vga.mk				# │
+include libc/irq/irq.mk				#─┘
 include libc/calls/calls.mk			#─┐
-include third_party/nsync/nsync.mk		# │
-include libc/runtime/runtime.mk			# ├──SYSTEMS RUNTIME
-include third_party/double-conversion/dc.mk	# │  You can issue system calls
+include libc/irq/irq.mk				# ├──SYSTEMS RUNTIME
+include third_party/nsync/nsync.mk		# │  You can issue system calls
+include libc/runtime/runtime.mk			# │
+include third_party/double-conversion/dc.mk	# │
 include libc/crt/crt.mk				# │
 include third_party/dlmalloc/dlmalloc.mk	#─┘
 include libc/mem/mem.mk				#─┐
@@ -340,6 +342,7 @@ COSMOPOLITAN_OBJECTS =			\
 	LIBC_RUNTIME			\
 	THIRD_PARTY_NSYNC		\
 	LIBC_ELF			\
+	LIBC_IRQ			\
 	LIBC_CALLS			\
 	LIBC_SYSV_CALLS			\
 	LIBC_VGA			\

examples/examples.mk

@@ -46,6 +46,7 @@ EXAMPLES_DIRECTDEPS =								\
 	LIBC_DNS								\
 	LIBC_FMT								\
 	LIBC_INTRIN								\
+	LIBC_IRQ								\
 	LIBC_LOG								\
 	LIBC_MEM								\
 	LIBC_NEXGEN32E								\

examples/vga2.c

@@ -26,6 +26,8 @@
 
 __static_yoink("vga_console");
 __static_yoink("_idt");
+__static_yoink("_AcpiMadtFlags");
+__static_yoink("_AcpiBootFlags");
 __static_yoink("EfiMain");
 
 int main(int argc, char *argv[]) {

libc/intrin/interrupts.S

@@ -25,6 +25,7 @@
 │ OTHER DEALINGS IN THE SOFTWARE.                                              │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/dce.h"
+#include "libc/intrin/kprintf.h"
 #include "libc/macros.internal.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/runtime/pc.internal.h"

libc/irq/acpi-fadt-init.S

@@ -0,0 +1,43 @@
+/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
+│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ This is free and unencumbered software released into the public domain.      │
+│                                                                              │
+│ Anyone is free to copy, modify, publish, use, compile, sell, or              │
+│ distribute this software, either in source code form or as a compiled        │
+│ binary, for any purpose, commercial or non-commercial, and by any            │
+│ means.                                                                       │
+│                                                                              │
+│ In jurisdictions that recognize copyright laws, the author or authors        │
+│ of this software dedicate any and all copyright interest in the              │
+│ software to the public domain. We make this dedication for the benefit       │
+│ of the public at large and to the detriment of our heirs and                 │
+│ successors. We intend this dedication to be an overt act of                  │
+│ relinquishment in perpetuity of all present and future rights to this        │
+│ software under copyright law.                                                │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,              │
+│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF           │
+│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.       │
+│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR            │
+│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,        │
+│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR        │
+│ OTHER DEALINGS IN THE SOFTWARE.                                              │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
+#include "libc/irq/acpi.internal.h"
+#include "libc/macros.internal.h"
+#include "libc/runtime/pc.internal.h"
+
+	.init.start 312,_init_acpi_fadt
+	push	%rdi
+	push	%rsi
+	call	_AcpiFadtInit
+	pop	%rsi
+	pop	%rdi
+	.init.end 312,_init_acpi_fadt
+	.data
+_AcpiBootFlags:
+	.short	kAcpiFadtLegacyDevices | kAcpiFadt8042
+	.endobj	_AcpiBootFlags,globl
+	.previous

libc/irq/acpi-fadt.c

@@ -0,0 +1,80 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ This is free and unencumbered software released into the public domain.      │
+│                                                                              │
+│ Anyone is free to copy, modify, publish, use, compile, sell, or              │
+│ distribute this software, either in source code form or as a compiled        │
+│ binary, for any purpose, commercial or non-commercial, and by any            │
+│ means.                                                                       │
+│                                                                              │
+│ In jurisdictions that recognize copyright laws, the author or authors        │
+│ of this software dedicate any and all copyright interest in the              │
+│ software to the public domain. We make this dedication for the benefit       │
+│ of the public at large and to the detriment of our heirs and                 │
+│ successors. We intend this dedication to be an overt act of                  │
+│ relinquishment in perpetuity of all present and future rights to this        │
+│ software under copyright law.                                                │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,              │
+│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF           │
+│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.       │
+│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR            │
+│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,        │
+│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR        │
+│ OTHER DEALINGS IN THE SOFTWARE.                                              │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
+#include "libc/intrin/kprintf.h"
+#include "libc/irq/acpi.internal.h"
+
+#ifdef __x86_64__
+
+textstartup static void _AcpiDsdtInit(uintptr_t dsdt_phy) {
+  const AcpiTableDsdt *dsdt;
+  size_t length;
+  if (!dsdt_phy) {
+    KWARNF("FADT: no DSDT");
+    return;
+  }
+  dsdt = _AcpiMapTable(dsdt_phy);
+  KINFOF("FADT: DSDT @ %p", dsdt);
+  length = dsdt->Header.Length;
+  if (length <= offsetof(AcpiTableDsdt, Aml)) {
+    KWARNF("DSDT: no AML?");
+    return;
+  }
+  /* TODO: parse AML to discover hardware configuration */
+}
+
+textstartup void _AcpiFadtInit(void) {
+  if (IsMetal()) {
+    const AcpiTableFadt *fadt;
+    size_t length;
+    uint16_t flags;
+    uintptr_t dsdt_phy = 0;
+    if (!_AcpiSuccess(_AcpiGetTable("FACP", 0, (void **)&fadt))) {
+      KINFOF("no FADT found");
+      return;
+    }
+    length = fadt->Header.Length;
+    KINFOF("FADT @ %p,+%#zx", fadt, length);
+    _Static_assert(offsetof(AcpiTableFadt, Dsdt) == 40);
+    _Static_assert(offsetof(AcpiTableFadt, BootFlags) == 109);
+    _Static_assert(offsetof(AcpiTableFadt, XDsdt) == 140);
+    if (length >= offsetof(AcpiTableFadt, BootFlags) + sizeof(fadt->BootFlags))
+    {
+      _AcpiBootFlags = flags = fadt->BootFlags;
+      KINFOF("FADT: boot flags %#x", (unsigned)flags);
+    }
+    if (length >= offsetof(AcpiTableFadt, XDsdt) + sizeof(fadt->XDsdt) &&
+        fadt->XDsdt) {
+      dsdt_phy = fadt->XDsdt;
+    } else if (length >= offsetof(AcpiTableFadt, Dsdt) + sizeof(fadt->Dsdt)) {
+      dsdt_phy = fadt->Dsdt;
+    }
+    _AcpiDsdtInit(dsdt_phy);
+  }
+}
+
+#endif /* __x86_64__ */

libc/irq/acpi-madt-init.S

@@ -0,0 +1,51 @@
+/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
+│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ This is free and unencumbered software released into the public domain.      │
+│                                                                              │
+│ Anyone is free to copy, modify, publish, use, compile, sell, or              │
+│ distribute this software, either in source code form or as a compiled        │
+│ binary, for any purpose, commercial or non-commercial, and by any            │
+│ means.                                                                       │
+│                                                                              │
+│ In jurisdictions that recognize copyright laws, the author or authors        │
+│ of this software dedicate any and all copyright interest in the              │
+│ software to the public domain. We make this dedication for the benefit       │
+│ of the public at large and to the detriment of our heirs and                 │
+│ successors. We intend this dedication to be an overt act of                  │
+│ relinquishment in perpetuity of all present and future rights to this        │
+│ software under copyright law.                                                │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,              │
+│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF           │
+│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.       │
+│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR            │
+│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,        │
+│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR        │
+│ OTHER DEALINGS IN THE SOFTWARE.                                              │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
+#include "libc/irq/acpi.internal.h"
+#include "libc/macros.internal.h"
+#include "libc/runtime/pc.internal.h"
+
+	.init.start 311,_init_acpi_madt
+	push	%rdi
+	push	%rsi
+	call	_AcpiMadtInit
+	pop	%rsi
+	pop	%rdi
+	.init.end 311,_init_acpi_madt
+	.data
+_AcpiMadtFlags:
+	.long	kAcpiMadtPcAtCompat
+	.endobj	_AcpiMadtFlags,globl
+	.previous
+	.bss
+_AcpiNumIoApics:
+	.skip	8
+	.endobj	_AcpiNumIoApics,globl
+_AcpiIoApics:
+	.skip	8
+	.endobj	_AcpiIoApics,globl
+	.previous

libc/irq/acpi-madt.c

@@ -0,0 +1,81 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ This is free and unencumbered software released into the public domain.      │
+│                                                                              │
+│ Anyone is free to copy, modify, publish, use, compile, sell, or              │
+│ distribute this software, either in source code form or as a compiled        │
+│ binary, for any purpose, commercial or non-commercial, and by any            │
+│ means.                                                                       │
+│                                                                              │
+│ In jurisdictions that recognize copyright laws, the author or authors        │
+│ of this software dedicate any and all copyright interest in the              │
+│ software to the public domain. We make this dedication for the benefit       │
+│ of the public at large and to the detriment of our heirs and                 │
+│ successors. We intend this dedication to be an overt act of                  │
+│ relinquishment in perpetuity of all present and future rights to this        │
+│ software under copyright law.                                                │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,              │
+│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF           │
+│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.       │
+│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR            │
+│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,        │
+│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR        │
+│ OTHER DEALINGS IN THE SOFTWARE.                                              │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
+#include "libc/inttypes.h"
+#include "libc/irq/acpi.internal.h"
+
+#ifdef __x86_64__
+
+textstartup void _AcpiMadtInit(void) {
+  if (IsMetal()) {
+    const AcpiTableMadt *madt;
+    size_t length, num_io_apics = 0;
+    const char *madt_end, *p;
+    const AcpiSubtableHeader *h;
+    const AcpiMadtIoApic **icp;
+    uint32_t flags;
+    if (!_AcpiSuccess(_AcpiGetTable("APIC", 0, (void **)&madt))) {
+      KINFOF("no MADT found");
+      return;
+    }
+    length = madt->Header.Length;
+    if (length < sizeof(*madt)) {
+      KDIEF("MADT has short length %#zx", length);
+    }
+    _AcpiMadtFlags = flags = madt->Flags;
+    KINFOF("MADT @ %p, flags %#" PRIx32, madt, flags);
+    madt_end = (char *)madt + length;
+    p = madt->Subtable;
+    while (p != madt_end) {
+      h = (const AcpiSubtableHeader *)p;
+      switch (h->Type) {
+        case kAcpiMadtIoApic:
+          ++num_io_apics;
+      }
+      p += h->Length;
+    }
+    KINFOF("MADT: %zu I/O APIC(s)", num_io_apics);
+    icp = _AcpiOsAllocate(num_io_apics * sizeof(const AcpiMadtIoApic *));
+    if (icp) {
+      _AcpiIoApics = icp;
+      p = madt->Subtable;
+      while (p != madt_end) {
+        h = (const AcpiSubtableHeader *)p;
+        switch (h->Type) {
+          case kAcpiMadtIoApic:
+            *icp++ = (const AcpiMadtIoApic *)p;
+        }
+        p += h->Length;
+      }
+      _AcpiNumIoApics = num_io_apics;
+    } else {
+      KWARNF("MADT: no memory for I/O APICs");
+    }
+  }
+}
+
+#endif /* __x86_64__ */

libc/irq/acpi-xsdt-init.S

@@ -0,0 +1,46 @@
+/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8     -*-│
+│vi: set et ft=asm ts=8 tw=8 fenc=utf-8                                     :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ This is free and unencumbered software released into the public domain.      │
+│                                                                              │
+│ Anyone is free to copy, modify, publish, use, compile, sell, or              │
+│ distribute this software, either in source code form or as a compiled        │
+│ binary, for any purpose, commercial or non-commercial, and by any            │
+│ means.                                                                       │
+│                                                                              │
+│ In jurisdictions that recognize copyright laws, the author or authors        │
+│ of this software dedicate any and all copyright interest in the              │
+│ software to the public domain. We make this dedication for the benefit       │
+│ of the public at large and to the detriment of our heirs and                 │
+│ successors. We intend this dedication to be an overt act of                  │
+│ relinquishment in perpetuity of all present and future rights to this        │
+│ software under copyright law.                                                │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,              │
+│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF           │
+│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.       │
+│ IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR            │
+│ OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,        │
+│ ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR        │
+│ OTHER DEALINGS IN THE SOFTWARE.                                              │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/dce.h"
+#include "libc/irq/acpi.internal.h"
+#include "libc/macros.internal.h"
+#include "libc/runtime/pc.internal.h"
+
+	.init.start 310,_init_acpi_xsdt
+	push	%rdi
+	push	%rsi
+	call	_AcpiXsdtInit
+	pop	%rsi
+	pop	%rdi
+	.init.end 310,_init_acpi_xsdt
+	.bss
+_AcpiXsdtNumEntries:
+	.skip	8
+	.endobj	_AcpiXsdtNumEntries,globl
+_AcpiXsdtEntries:
+	.skip	8
+	.endobj	_AcpiXsdtEntries,globl
+	.previous