add paging fork of aseg; totally not working yet.

[netwatch.git] / aseg-paging / pagingstub.c

diff --git a/aseg-paging/pagingstub.c b/aseg-paging/pagingstub.c
new file mode 100644 (file)
index 0000000..6c85157
--- /dev/null
+++ b/aseg-paging/pagingstub.c
@@ -0,0 +1,128 @@
+#include <io.h>
+#include <smram.h>
+#include <video_defines.h>
+#include <minilib.h>
+#include <smi.h>
+#include <pci-bother.h>
+#include "../net/net.h"
+#include "vga-overlay.h"
+
+#include "vm_flags.h"
+#include "pagetable.h"
+
+void set_cr0(unsigned int);
+
+extern int entry_initialized;
+extern int _bss, _bssend, _end;
+void smi_entry();
+#define get_cr0() \
+    ({ \
+        register unsigned int _temp__; \
+        asm volatile("mov %%cr0, %0" : "=r" (_temp__)); \
+        _temp__; \
+    })
+
+
+#define set_cr3(value) \
+    { \
+        register unsigned int _temp__ = (value); \
+        asm volatile("mov %0, %%cr3" : : "r" (_temp__)); \
+     }
+#define        CR0_PG  0x80000000
+
+#define MAP_FLAGS      (PTE_PRESENT | PTE_READ_WRITE)
+
+void * pt_setup(int smbase) {
+       int i;
+       outb(0x80, 0x51);
+
+       /* The page directory and page table live at SMBASE and SMBASE + 0x1000,
+        * respectively; clear them. */
+       int * pagedirectory = (int *) smbase;
+       int * pagetable = (int *) (smbase + 0x1000);
+
+       /* Clear out the page directory except for one entry pointing to the
+        * page table, and clear the page table entirely. */
+       outb(0x80, 0x52);
+       pagedirectory[0] = (smbase + 0x1000) | PTE_PRESENT | PTE_READ_WRITE;
+       outb(0x80, 0x53);
+       for (i = 1; i < 1024; i++)
+       {
+               pagedirectory[i] = 0;
+       }
+
+       outb(0x80, 0x54);
+       for (i = 0; i < 1024; i++)
+       {
+               pagetable[i] = 0;
+       }
+       outb(0x80, 0x55);
+
+       /* The page at 0x10000 - 0x10FFF points to the SMI entry point,
+        * SMBASE + 0x8000. */
+       pagetable[16] = (0x8000 + smbase) | MAP_FLAGS;
+
+       /* 0x11000 to 0x1EFFF map to the rest of ASEG up to SMBASE + 0xF000;
+        * the page containing the saved state is not mappped to our code
+        * region.  */
+
+       for (i = 0; i < 8; i++)
+       {
+               pagetable[17 + i] = (i * 0x1000 + smbase) | MAP_FLAGS;
+       }
+
+       for (i = 0; i < 6; i++)
+       {
+               pagetable[25 + i] = (smbase + 0x9000 + i * 0x1000) | MAP_FLAGS;
+       }
+
+       outb(0x80, 0x56);
+       /* Map 0xA8000 to itself. */
+
+       for (i = 0; i < 32; i++) { 
+               pagetable[0xA0 + i] = (0xA0000 + i * 0x1000) | MAP_FLAGS;
+       }
+
+       /* Map 0x200000 to TSEG */
+       for (i = 0; i < 128; i++) {
+               pagetable[0x200 + i] = (0x1FF80000 + i * 0x1000) | MAP_FLAGS;
+       }
+
+       /* Map 0x300000 -> 0x200000, so we can copy our code out of
+        * RAM the first time around */
+       for (i = 0; i < 256; i++) {
+       /*      pagetable[0x300 + i] = (0x200000 + i * 0x1000) | MAP_FLAGS;
+        */
+               pagetable[0x200 + i] = (0x200000 + i * 0x1000) | MAP_FLAGS;
+       }
+
+       outb(0x80, 0x57);
+       return pagedirectory;
+}
+
+void c_entry(void)
+{
+//     unsigned char *bp;
+
+       outb(0x80, 0x41);
+       char * pagedir = pt_setup(0xA0000);
+       outb(0x80, 0x43);
+       set_cr3((int)pagedir);
+       outb(0x80, 0xA5);
+
+       /* Turn paging on */
+       set_cr0(get_cr0() | CR0_PG);
+       outb(0x80, 0xAA);
+       if (!entry_initialized) {
+               outb(0x80, 0xAB);
+/*
+               for (bp = (void *)0x200000; (void *)bp < (void *)&_bss; bp++)
+                       *bp = *(bp + 0x100000);
+
+               for (bp = (void *)&_bss; (void *)bp < (void *)&_bssend; bp++)
+                       *bp = 0;
+                       */
+       }
+
+       smi_entry();
+}