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Move the pmap_kenter(KERNBASE, 0) a bit earlier so that it works for

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the hasbrokenint12 tunable case too.  (with some related and unrelated
style fixes)

Submitted by:  bde
This commit is contained in:
Peter Wemm 2003-10-10 17:43:42 +00:00
parent 64024d1cc8
commit 4dab350282
1 changed files with 24 additions and 15 deletions
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39
sys/i386/i386/machdep.c
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@ -1504,9 +1504,16 @@ getmemsize(int first)
char *cp;
struct bios_smap *smap;
/*
* Change the mapping of the page at address zero from r/o to r/w
* so that vm86 can scribble on this page. Note that this page is
* not in the general free page pool.
*/
pmap_kenter(KERNBASE, 0);
hasbrokenint12 = 0;
TUNABLE_INT_FETCH("hw.hasbrokenint12", &hasbrokenint12);
bzero(&vmf, sizeof(struct vm86frame));
bzero(&vmf, sizeof(vmf));
bzero(physmap, sizeof(physmap));
basemem = 0;
@ -1555,14 +1562,10 @@ getmemsize(int first)
pmap_kenter(KERNBASE + pa, pa);
/*
* Map the page at address zero for the bios code to use.
* Note that page zero is not in the general page pool.
*/
pmap_kenter(KERNBASE, 0);
/*
* if basemem != 640, map pages r/w into vm86 page table so
* that the bios can scribble on it.
* Map pages between basemem and ISA_HOLE_START, if any, r/w into
* the vm86 page table so that vm86 can scribble on them using
* the vm86 map too. XXX: why 2 ways for this and only 1 way for
* page 0, at least as initialized here?
*/
pte = (pt_entry_t *)vm86paddr;
for (i = basemem / 4; i < 160; i++)
@ -1645,20 +1648,26 @@ next_run: ;
}
}
if (basemem == 0) {
/*
* XXX this function is horribly organized and has to the same
* things that it does above here.
*/
if (basemem == 0)
basemem = 640;
}
if (basemem > 640) {
printf("Preposterous BIOS basemem of %uK, truncating to 640K\n",
basemem);
printf(
"Preposterous BIOS basemem of %uK, truncating to 640K\n",
basemem);
basemem = 640;
}
/*
* Let vm86 scribble on pages between basemem and
* ISA_HOLE_START, as above.
*/
for (pa = trunc_page(basemem * 1024);
pa < ISA_HOLE_START; pa += PAGE_SIZE)
pmap_kenter(KERNBASE + pa, pa);
pte = (pt_entry_t *)vm86paddr;
for (i = basemem / 4; i < 160; i++)
pte[i] = (i << PAGE_SHIFT) | PG_V | PG_RW | PG_U;