Clean up vga_overlay a bit to split out the VGA-specific code to strblit

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

diff --git a/aseg-paging/pagingstub.c b/aseg-paging/pagingstub.c
index 161dc1f52661c023cbd721a79f81af2ff23886f9..7d430b92c5e200d1efb2d61d3f3b9510833972fb 100644 (file)
--- a/aseg-paging/pagingstub.c
+++ b/aseg-paging/pagingstub.c
@@ -40,6 +40,8 @@ static unsigned long *pd;
 
 extern int _bss, _bssend, _end;
 
+static unsigned long curmapped = 0xFFFFFFFF;
+
 unsigned long v2p(void *virt)
 {
        unsigned long _virt = (unsigned long)virt;
@@ -51,6 +53,11 @@ unsigned long v2p(void *virt)
                return _virt;
        if (_virt >= 0x200000 && _virt < 0x300000)
                return _virt - 0x200000 + /* XXX */ 0x1FF82000;
+       if (_virt >= 0x1F0000 && _virt < 0x1F2000)
+               return _virt - 0x1F0000 + 0x1FF80000;
+       if ((_virt & ~0xFFF) == 0x4000)
+               return _virt - 0x4000 + curmapped;
+       
        outputf("WARNING: v2p(%08x)", _virt);
        return 0xFFFFFFFF;
 }
@@ -62,14 +69,21 @@ void *p2v(unsigned long phys)
        
        if (phys >= 0xA0000 && phys < 0xC0000)
                return (void*)phys;
-       if (phys >= 0x1FF80000 && phys < 0x20000000)
+       if (phys >= 0x1FF82000 && phys < 0x20000000)
                return (void*)(phys - 0x1FF82000 + 0x200000);
-       outputf("WARNING: p2v(%08x)", phys);
-       return (void *)0xFFFFFFFF;
+       if (phys >= 0x1FF80000 && phys < 0x1FF82000)
+               return (void*)(phys - 0x1FF80000 + 0x1F0000);
+               
+       if ((phys & ~0xFFF) != curmapped)       /* If it's not mapped, map it in. */
+       {
+               curmapped = phys & ~0xFFF;
+               addmap(0x4000, curmapped);
+               asm volatile("invlpg 0x4000");
+       }
+       return (void*)(0x4000 + (phys & 0xFFF));
 }
 
-
-inline int pt_addmap(unsigned long *pd, unsigned long vaddr, unsigned long paddr)
+int addmap(unsigned long vaddr, unsigned long paddr)
 {
        unsigned long pde = ((unsigned long *)p2v((unsigned long)pd))[PDE_FOR(vaddr)];
        unsigned long *pt;
@@ -83,13 +97,28 @@ inline int pt_addmap(unsigned long *pd, unsigned long vaddr, unsigned long paddr
        return 0;
 }
 
-static void * pt_setup(int tseg_start, int tseg_size) {
+void *demap(unsigned long client_pd, unsigned long vaddr)
+{
+       unsigned long pde = ((unsigned long *)p2v(client_pd))[PDE_FOR(vaddr)];
+       unsigned long pte;
+       
+       if (!(pde & PTE_PRESENT))
+               return (void*)0x0;
+       pte = ((unsigned long *)p2v(ADDR_12_MASK(pde)))[PTE_FOR(vaddr)];
+       if (!(pte & PTE_PRESENT))
+               return (void*)0x0;
+       return p2v((pte & ~0xFFF) + (vaddr & 0xFFF));
+}
+
+static void pt_setup(int tseg_start, int tseg_size) {
        int i;
 
        /* The page directory and page table live at TSEG and TSEG + 0x1000,
         * respectively. */
        unsigned long *pagedirectory = (unsigned long *) tseg_start;
        unsigned long *pagetable = (unsigned long *) (tseg_start + 0x1000);
+       
+       pd = pagedirectory;
 
        /* Clear out the page directory except for one entry pointing to the
         * page table, and clear the page table entirely. */
@@ -102,18 +131,20 @@ static void * pt_setup(int tseg_start, int tseg_size) {
 
        /* Map 0x0A0000:0x0BFFFF to itself. */
        for (i = 0; i < 32; i++)
-               pt_addmap(pagedirectory, 0xA0000 + i * 0x1000, 0xA0000 + i * 0x1000);
+               addmap(0xA0000 + i * 0x1000, 0xA0000 + i * 0x1000);
 
-       /* Map 0x200000:0x300000 to TSEG */
+       /* Map 0x200000:0x300000 to TSEG data */
        for (i = 0; i < 256; i++)
-               pt_addmap(pagedirectory, 0x200000 + i * 0x1000, tseg_start + 0x2000 + i * 0x1000);
+               addmap(0x200000 + i * 0x1000, tseg_start + (i + 2) * 0x1000);
 
        /* Map 0x300000:0x400000 to 0x200000, so we can copy our code out of
         * RAM the first time around */
        for (i = 0; i < 256; i++)
-               pt_addmap(pagedirectory, 0x300000 + i * 0x1000, 0x200000 + i * 0x1000);
+               addmap(0x300000 + i * 0x1000, 0x200000 + i * 0x1000);
 
-       return pagedirectory;
+       /* Map 0x1F0000:0x1F2000 to TSEG paging info */
+       for (i = 0; i < 2; i++)
+               addmap(0x1F0000 + i * 0x1000, tseg_start + i * 0x1000);
 }
 
 void c_entry(void)
@@ -122,7 +153,7 @@ void c_entry(void)
 
        outb(0x80, 0x01);       
        if (!initialized)
-               pd = pt_setup(0x1FF80000, 0x80000);
+               pt_setup(0x1FF80000, 0x80000);
        outb(0x80, 0x02);
                
        /* Enable paging. */