mirrors/cosmopolitan
1
0
Fork 0
mirror of https://github.com/jart/cosmopolitan.git synced 2025-06-27 14:58:30 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Fix bugs and have emulator emulate itself

Browse source
This commit is contained in:
Justine Tunney 2020-08-31 05:17:31 -07:00
parent 5aabacb361
commit bd29223891
111 changed files with 1283 additions and 2073 deletions
Download patch file Download diff file Expand all files Collapse all files

98
tool/build/lib/pml4t.c
View file

@ -52,6 +52,40 @@ static uint64_t *GetPageTable(pml4t_t p, long i, void *NewPhysicalPage(void)) {
return res;
}
static void PtFinder(uint64_t *a, uint64_t *b, uint64_t n, pml4t_t pd, int k) {
uint64_t e, c;
unsigned start;
for (start = (*b >> k) & 511; *b - *a < n && ((*b >> k) & 511) >= start;) {
e = pd[(*b >> k) & 511];
c = ROUNDUP(*b + 1, 1 << k);
if (!IsValidPage(e)) {
*b = c;
} else if (k && *b - *a + (c - *b) > n) {
PtFinder(a, b, n, UnmaskPageAddr(e), k - 9);
} else {
*a = *b = c;
}
}
}
/**
* Locates free memory range.
*
* @param h specifies signedness and around where to start searching
* @return virtual page address with size bytes free, or -1 w/ errno
*/
int64_t FindPml4t(pml4t_t pml4t, uint64_t h, uint64_t n) {
uint64_t a, b;
n = ROUNDUP(n, 4096) >> 12;
a = b = (h & 0x0000fffffffff000) >> 12;
if (!n || n > 0x10000000) return einval();
PtFinder(&a, &b, n, pml4t, 9 * 3);
if (b > 0x0000001000000000) return eoverflow();
if (h < 0x0000800000000000 && b > 0x0000000800000000) return eoverflow();
if (b - a < n) return enomem();
return a << 12;
}
/**
* Maps virtual page region to system memory region.
*
@ -95,70 +129,6 @@ int RegisterPml4t(pml4t_t pml4t, int64_t v, int64_t r, size_t n,
return enomem();
}
/**
* Locates free memory range.
*
* @param hint specifies signedness and around where to start searching
* @return virtual page address with size bytes free, or -1 w/ errno
*/
int64_t FindPml4t(pml4t_t pml4t, int64_t hint, uint64_t size,
void *NewPhysicalPage(void)) {
int64_t res;
unsigned short a[4], b[4];
uint64_t *pdpt, *pdt, *pd, have;
if (!size) return einval();
have = 0;
size = ROUNDUP(size, 4096) >> 12;
b[0] = a[0] = (hint >> 39) & 511;
b[1] = a[1] = (hint >> 30) & 511;
b[2] = a[2] = (hint >> 21) & 511;
a[3] = 0;
for (; b[0] < 512; ++b[0]) {
if (!(pdpt = GetPageTable(pml4t, b[0], NewPhysicalPage))) return -1;
for (; b[1] < 512; ++b[1]) {
if (!(pdt = GetPageTable(pdpt, b[1], NewPhysicalPage))) return -1;
for (; b[2] < 512; ++b[2]) {
if (!IsValidPage(pdt[b[2]])) {
if ((have += 512) >= size) {
return MakeAddress(a);
}
} else if (size < 0x200) {
pd = UnmaskPageAddr(pdt[b[2]]);
for (b[3] = 0; b[3] < 512; ++b[3]) {
if (!IsValidPage(pd[b[3]])) {
if ((have += 1) >= size) {
return MakeAddress(a);
}
} else {
have = 0;
a[0] = b[0];
a[1] = b[1];
a[2] = b[2];
a[3] = b[3];
if ((a[3] += 1) == 512) {
a[3] = 0;
if ((a[2] += 1) == 512) {
a[2] = 0;
if ((a[1] += 1) == 512) {
a[1] = 0;
a[0] += 1;
if (a[0] == 256 || a[0] == 512) {
return eoverflow();
}
}
}
}
}
}
}
}
a[2] = 0;
}
a[1] = 0;
}
return enomem();
}
/**
* Unmaps pages and frees page tables.
*/