start of 0.0.9 branch, using multiboot this time

1 files changed, 169 insertions, 25 deletions

diff --git a/src/kernel/main.c b/src/kernel/main.c
index 9ad9d1c..74fd8bf 100644
--- a/src/kernel/main.c
+++ b/src/kernel/main.c
@@ -21,33 +21,177 @@ OF THIS SOFTWARE.
 #include "files.h"
 #include "mem.h"
 #include "proc.h"
-#include "misc.h"
-
-void _start(void) {
-  *(uint16_t *)0x0000200e = 0x0000;
-
-  *(uint32_t *)0x0000050c = (uint32_t)allocate_pages(16 * sizeof(struct file_handle_info), 2);
-  for (struct file_handle_info *i = FILE_HANDLES, *l = FILE_HANDLES + 65536; i < l; ++i)
-    i->first_sector = 0;
-
-  *(uint32_t *)0x00000510 = (uint32_t)allocate_pages(16 * sizeof(struct proc_info), 2);
-  for (struct proc_info *i = PROCS, *l = PROCS + 65536; i < l; ++i)
-    i->memory_start = 0;
-
-  uint16_t pages_free = 0, pages_total = 0;
-  for (uint16_t *i = MMAP; i < MMAP + 0x1000; ++i)
-    switch (*i) {
-    case 1:
-      continue;
-    case 0:
-      ++pages_free;
+#include <stdbool.h>
+
+extern uint32_t info_pointer;
+
+enum tag_type {
+  BOOT_COMMAND     =  1,
+  LOADER_NAME      =  2,
+  BOOT_MODULES     =  3,
+  MEMORY_INFO      =  4,
+  BOOT_DEVICE      =  5,
+  MEMORY_MAP       =  6,
+  VBE_INFO         =  7,
+  FBUF_INFO        =  8,
+  ELF_SYMBOLS      =  9,
+  APM_TABLE        = 10,
+  EFI_I386_TABLE   = 11,
+  EFI_AMD64_TABLE  = 12,
+  SMBIOS_TABLE     = 13,
+  RSDP_ACPI1       = 14,
+  RSDP_ACPI2       = 15,
+  NETWORK_INFO     = 16,
+  EFI_MEMORY_MAP   = 17,
+  EFI_SERVICES     = 18,
+  EFI_I386_HANDLE  = 19,
+  EFI_AMD64_HANDLE = 20,
+  IMAGE_BASE_ADDR  = 21
+};
+
+struct tag_start {
+  uint32_t type;
+  uint32_t size;
+  uint8_t rest;
+} __attribute__ ((__packed__));
+
+struct boot_device_tag {
+  uint32_t bios_device;
+  uint32_t partition;
+  uint32_t subpartition;
+} __attribute__ ((__packed__));
+
+enum mem_type {
+  AVAILABLE = 1,
+  ACPI      = 3,
+  PRESERVE  = 4,
+  DEFECTIVE = 5
+};
+
+struct boot_device_tag boot_device;
+bool have_boot_device = false;
+bool have_mmap = false;
+
+enum error_codes {
+  NO_BOOT_DEVICE = 0,
+  NO_MMAP        = 1,
+  INSUFF_MEMORY  = 2
+};
+
+uint32_t main(void) {
+  uint32_t info_size = *(uint32_t *)info_pointer;
+  struct tag_start *tag_pointer = (struct tag_start *)(info_pointer + 2);
+
+  while (tag_pointer->type) {
+    switch (tag_pointer->type) {
+
+    case BOOT_DEVICE:
+      boot_device = *(struct boot_device_tag *)&tag_pointer->rest;
+      have_boot_device = true;
+      put_sz("Boot device: 0x");
+      put_32_hex(boot_device.bios_device);
+      if (boot_device.partition != 0xffffffff) {
+        put_sz(", 0x");
+        put_32_hex(boot_device.partition);
+        if (boot_device.subpartition != 0xffffffff) {
+          put_sz(", 0x");
+          put_32_hex(boot_device.subpartition);
+        }
+      }
+      put_char('\n');
+      break;
+
+    case MEMORY_MAP:
+      mmap_start = (struct mmap_entry *)((uint32_t)&tag_pointer->rest + 8);
+      uint32_t size = *(uint32_t *)&tag_pointer->rest;
+      struct mmap_entry *next = mmap_start;
+      struct mmap_entry **fill_last = &mmap_start;
+      uint32_t usable = 0;
+      while (next) {
+        if (!(next->base & 0xffffffff00000000)) {
+          *fill_last = next;
+          fill_last = &next->next;
+          if ((next->base + next->length - 1) & 0xffffffff00000000)
+            next->length = 1 + ~(next->base);
+          put_sz("Memory: 0x");
+          put_32_hex((uint32_t)(next->base >> 32));
+          put_char('_');
+          put_32_hex((uint32_t)next->base);
+          put_sz(" - ");
+          put_32_hex((uint32_t)(next->length >> 32));
+          put_char('_');
+          put_32_hex((uint32_t)next->length);
+          switch (next->whose) {
+          case AVAILABLE:
+            put_sz(": usable\n");
+            next->whose = FREE;
+            usable += next->length;
+            break;
+          case ACPI:
+            put_sz(": ACPI info\n");
+            next->whose = HARDWARE;
+            break;
+          case PRESERVE:
+            put_sz(": hardware use\n");
+            next->whose = HARDWARE;
+            break;
+          case DEFECTIVE:
+            put_sz(": defective\n");
+            next->whose = HARDWARE;
+            break;
+          default:
+            put_sz(": unrecognized type, assuming hardware use\n");
+            next->whose = HARDWARE;
+            break;
+          }
+        }
+        next = next->next = (struct mmap_entry *)((uint32_t)next + size);
+      }
+
+      put_sz("Total usable memory: 0x");
+      put_32_hex(usable);
+      put_char('\n');
+
+      bool clean;
+      do {
+        clean = true;
+        for (struct mmap_entry *current = mmap_start; current; current = current->next)
+          for (struct mmap_entry *against = mmap_start; against; against = against->next)
+            if ((current->base + current->length == against->base) &&
+                (current->whose == against->whose)) {
+              current->length += against->length;
+              if (against == mmap_start)
+                mmap_start = against->next;
+              else {
+                for (current = mmap_start; current->next != against; current = current->next)
+                  ;
+                current->next = against->next;
+              }
+              clean = false;
+            }
+      } while (clean);
+
+      have_mmap = true;
+      break;
+
     default:
-      ++pages_total;
+      put_sz("Ignoring multiboot tag 0x");
+      put_32_hex(tag_pointer->type);
+      put_char('\n');
+
     }
-  put_16(pages_free);
-  put_sz(" of ");
-  put_16(pages_total);
-  put_sz(" pages free.\n");
+    tag_pointer = (struct tag_start *)((uint8_t *)tag_pointer + tag_pointer->size);
+  };
+
+  if (!have_boot_device)
+    return NO_BOOT_DEVICE;
+  if (!have_mmap)
+    return NO_MMAP;
+
+  if (!((proc_table = allocate_block(sizeof(struct proc_info) * 65536, KERNEL)) &&
+        (file_table = allocate_block(sizeof(struct file_info) * 65536, KERNEL))))
+    return INSUFF_MEMORY;
+  ;
 
   put_sz("Welcome to Portland version 0.0.8!\n");
   while (1)