[MODERN FEATURES] ACPI tables

emul

@@ -58,7 +58,7 @@ function main() {
   make all || exit 1
   util/build_iso.sh || exit 1
   echo > serial.log
-  emulator="qemu-system-x86_64 -cdrom mittos64.iso -serial file:serial.log ${EMULPARAM[@]}"
+  emulator="qemu-system-x86_64 -cdrom mittos64.iso -serial file:serial.log -smp 4 ${EMULPARAM[@]}"
   debugger=$(which x86_64-elf-linux-gdb)
 
   if [[ (-n ${EMULVNC}) ]]; then

kernel/arch/acpi.c

@@ -0,0 +1,117 @@
+#include <acpi.h>
+#include <stdint.h>
+#include <debug.h>
+#include <mem.h>
+#include <string.h>
+#include <multiboot.h>
+
+RSDP_st *find_rsdp()
+{
+  // The Root System Description Pointer (RSDP) should be found either
+  // - in the first 1 KB of the EBDA
+  // - between 0xE0000 and 0xFFFFF
+  // We'll only try the second alternative for now
+
+  uintptr_t start = KERNEL_OFFSET + 0xE0000;
+  uintptr_t end = KERNEL_OFFSET + 0xFFFFF;
+
+  uint8_t *p = (void *)start;
+  while((uintptr_t)p < end)
+  {
+    // The RSDP is identified by a signature string
+    if(!(memcmp(p, "RSD PTR ", 8)))
+    {
+      // Make sure we got it right by calculating the checksum
+      uint8_t checksum = 0;
+      for(int i = 0; i < 20; i++)
+        checksum += p[i];
+      if(!checksum)
+        break;
+    }
+    // The RSDP must be 16-byte aligned
+    p = incptr(p, 16);
+  }
+  if((uintptr_t)p >= end)
+    return 0;
+  return (void *)p;
+}
+
+SDT_header *find_SDT(RSDP_st *rsdp, char *signature)
+{
+  // Scan through the RSDT or XSDT for a header with the wanted signature
+
+  // Read RSDT if revision <= 1.0
+  // else read XSDT
+  unsigned int bpp = (!rsdp->revision)?4:8;
+  SDT_header *rsdt = (bpp == 4) ? P2V(rsdp->RSDT_p) : P2V(rsdp->XSDT_p);
+
+  int entries = (rsdt->length - sizeof(SDT_header))/bpp;
+  for(int i = 0; i < entries; i++)
+  {
+    // 32 bit pointers if revision <= 1.0
+    // otherwise 64 bit pointers
+    SDT_header *h = (bpp == 4) ?
+      P2V(*(uint32_t*)&rsdt->data[i*bpp]) :
+      P2V(*(uint64_t*)&rsdt->data[i*bpp]);
+
+    // Return pointer if signature is correct
+    if(!memcmp(h->signature, signature, 4))
+      return h;
+  }
+  return 0;
+}
+
+void parse_MADT(SDT_header *header)
+{
+  MADT_header *madt = (MADT_header *)header->data;
+  // Save the memory mapping of the local APIC
+
+  // TODO: In bochs, there are MADT entries with 0 length. I assume parsing should stop here.
+  // TODO: Look this up
+  for(MADT_field *f = (void*)madt->fields;
+      (uintptr_t)f < (uintptr_t)madt + header->length && f->length;
+      f = incptr(f, f->length))
+  {
+    switch(f->type)
+    {
+      case 0: // Processor Local APIC entry
+        debug_info("ACPI - Processor id:%x LAPIC:%x", f->proc.proc_ID, f->proc.APIC_ID);
+        if(f->proc.flags & 0x1)
+        {
+          debug(" enabled");
+        }
+        debug("\n");
+        break;
+      case 1: // I/O APIC entry
+        debug_info("ACPI - IOAPIC id:%x address:%x\n", f->IOAPIC.APIC_ID, f->IOAPIC.address);
+        break;
+      case 2: // Interrupt Source Override
+        debug_info("ACPI - Interrupt source override %x->%x\n", f->ISO.irq, f->ISO.interrupt);
+        break;
+      default:
+        break;
+    }
+  }
+}
+
+void acpi_init()
+{
+  RSDP_st *rsdp;
+  if(!(rsdp = mboot_data.rsdp))
+  {
+    if(!(rsdp = find_rsdp()))
+    {
+    debug_error("PANIC: ACPI - No RSDP found!");
+    for(;;);
+    }
+  }
+
+  debug_info("ACPI - ACPI version %s\n", (rsdp->revision)?"2.0":"1.0");
+
+  // Scan for MADT
+  SDT_header *madt = find_SDT(rsdp, "APIC");
+  // Read processor info from MADT
+  parse_MADT(madt);
+  // Ignore all other tables for now
+
+}

kernel/boot/kmain.c

@@ -7,6 +7,7 @@
 #include <thread.h>
 #include <process.h>
 #include <cpuid.h>
+#include <acpi.h>
 
 void thread_function()
 {
@@ -31,11 +32,8 @@ int kmain(uint64_t multiboot_magic, void *multiboot_data)
   gdt_init();
   scheduler_init();
   pic_init();
+  acpi_init();
 
-  debug_info("CPUID - max function number: Normal:%x, Extended:%x\n", cpuid_max, cpuid_maxx);
-  debug_info("CPUID - has MSR:%d\n", CPUID_FEATURE_MSR);
-  debug_info("CPUID - has APIC:%d\n", CPUID_FEATURE_APIC);
-  debug_info("CPUID - has SYSCALL:%d\n", CPUID_FEATURE_SYSCALL);
 
   process_t *p1 = process_spawn(0);
   process_t *p2 = process_spawn(p1);

kernel/boot/multiboot.c

@@ -70,6 +70,11 @@ void parse_multiboot2()
         mboot_data.mmap = tag->data;
         debug_ok("MBOOT2 - handle ");
         break;
+      case MBOOT2_ACPI_V1:
+      case MBOOT2_ACPI_V2:
+        mboot_data.rsdp = &tag->data;
+        debug_ok("[MBOOT2] %x handle ", mboot_data.rsdp);
+        break;
       default:
         debug_warning("MBOOT2 - ignore ");
         break;
@@ -129,6 +134,8 @@ int multiboot_page_used(uintptr_t addr)
     mboot2_tags_head *data = mboot_data.data;
     if(overlapsz(addr, PAGE_SIZE, V2P(data), data->total_size))
       return 1;
+    if(mboot_data.rsdp && overlapsz(addr, PAGE_SIZE, mboot_data.rsdp, 1))
+      return 1;
   }
   return 0;
 }

kernel/include/acpi.h

@@ -0,0 +1,63 @@
+#pragma once
+#include <stdint.h>
+
+typedef struct RSDP_st
+{
+  unsigned char signature[8];
+  uint8_t checksum;
+  unsigned char OEMID[6];
+  uint8_t revision;
+  uint32_t RSDT_p;
+  // The following are only available if revision != 0
+  uint32_t length;
+  uint64_t XSDT_p;
+  uint8_t checksum2;
+  uint8_t reserved[3];
+}__attribute__ ((packed)) RSDP_st;
+
+typedef struct SDT_header
+{
+  unsigned char signature[4];
+  uint32_t length;
+  uint8_t revision;
+  uint8_t checksum;
+  unsigned char OEMID[6];
+  unsigned char OEMtable[8];
+  uint32_t OEMrevision;
+  uint32_t CreatorID;
+  uint32_t CreatorRevision;
+  uint8_t data[];
+}__attribute__ ((packed)) SDT_header;
+
+typedef struct MADT_header
+{
+  uint32_t LCA;
+  uint32_t flags;
+  uint8_t fields[];
+}__attribute__((packed)) MADT_header;
+typedef struct MADT_field
+{
+  uint8_t type;
+  uint8_t length;
+  union{
+    struct{
+      uint8_t proc_ID;
+      uint8_t APIC_ID;
+      uint32_t flags;
+    }__attribute__((packed)) proc;
+    struct {
+      uint8_t APIC_ID;
+      uint8_t reserved;
+      uint32_t address;
+      uint32_t base;
+    }__attribute__((packed)) IOAPIC;
+    struct {
+      uint8_t bus;
+      uint8_t irq;
+      uint32_t interrupt;
+      uint16_t flags;
+    }__attribute__((packed)) ISO;
+  };
+}__attribute__((packed)) MADT_field;
+
+void acpi_init();

kernel/include/multiboot.h

@@ -80,6 +80,8 @@ typedef struct {
   #define MBOOT2_CMDLINE 1
   #define MBOOT2_BOOTLOADER 2
   #define MBOOT2_MMAP 6
+  #define MBOOT2_ACPI_V1 14
+  #define MBOOT2_ACPI_V2 15
 
   // Multiboot tags are padded to a multiple of 8 bytes
   #define next_tag(tag) ((void *)((((uintptr_t)tag) + tag->size + 7) & ~0x7))
@@ -92,6 +94,7 @@ typedef struct {
     char *bootloader;
     void *mmap;
     uint32_t mmap_size;
+    void *rsdp;
   };
   extern struct mboot_data_st mboot_data;