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Basic VM and other minor improvements.

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Not complete, probably not fully debugged or optimized.
This commit is contained in:
Ben Gras
2008-11-19 12:26:10 +00:00
parent c888305e21
commit c078ec0331
273 changed files with 10814 additions and 4305 deletions
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676
kernel/arch/i386/memory.c
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@@ -1,20 +1,26 @@
#include "../../kernel.h"
#include "../../proc.h"
#include "../../vm.h"
#include <minix/type.h>
#include <minix/syslib.h>
#include <minix/sysutil.h>
#include <string.h>
#include <sys/vm.h>
#include <sys/vm_i386.h>
#include <minix/portio.h>
#include "proto.h"
#include "../../proto.h"
#include "../../debug.h"
/* VM functions and data. */
PRIVATE int vm_needs_init= 1;
PRIVATE u32_t vm_cr3;
PUBLIC u32_t kernel_cr3;
extern u32_t cswitch;
u32_t last_cr3 = 0;
FORWARD _PROTOTYPE( void phys_put32, (phys_bytes addr, u32_t value) );
FORWARD _PROTOTYPE( u32_t phys_get32, (phys_bytes addr) );
@@ -22,6 +28,13 @@ FORWARD _PROTOTYPE( void vm_set_cr3, (u32_t value) );
FORWARD _PROTOTYPE( void set_cr3, (void) );
FORWARD _PROTOTYPE( void vm_enable_paging, (void) );
#if DEBUG_VMASSERT
#define vmassert(t) { \
if(!(t)) { minix_panic("vm: assert " #t " failed\n", __LINE__); } }
#else
#define vmassert(t) { }
#endif
/* *** Internal VM Functions *** */
PUBLIC void vm_init(void)
@@ -31,31 +44,35 @@ PUBLIC void vm_init(void)
phys_bytes vm_dir_base, vm_pt_base, phys_mem;
u32_t entry;
unsigned pages;
struct proc* rp;
if (!vm_size)
panic("i386_vm_init: no space for page tables", NO_NUM);
minix_panic("i386_vm_init: no space for page tables", NO_NUM);
if(vm_running)
return;
/* Align page directory */
o= (vm_base % PAGE_SIZE);
o= (vm_base % I386_PAGE_SIZE);
if (o != 0)
o= PAGE_SIZE-o;
o= I386_PAGE_SIZE-o;
vm_dir_base= vm_base+o;
/* Page tables start after the page directory */
vm_pt_base= vm_dir_base+PAGE_SIZE;
vm_pt_base= vm_dir_base+I386_PAGE_SIZE;
pt_size= (vm_base+vm_size)-vm_pt_base;
pt_size -= (pt_size % PAGE_SIZE);
pt_size -= (pt_size % I386_PAGE_SIZE);
/* Compute the number of pages based on vm_mem_high */
pages= (vm_mem_high-1)/PAGE_SIZE + 1;
pages= (vm_mem_high-1)/I386_PAGE_SIZE + 1;
if (pages * I386_VM_PT_ENT_SIZE > pt_size)
panic("i386_vm_init: page table too small", NO_NUM);
minix_panic("i386_vm_init: page table too small", NO_NUM);
for (p= 0; p*I386_VM_PT_ENT_SIZE < pt_size; p++)
{
phys_mem= p*PAGE_SIZE;
phys_mem= p*I386_PAGE_SIZE;
entry= phys_mem | I386_VM_USER | I386_VM_WRITE |
I386_VM_PRESENT;
if (phys_mem >= vm_mem_high)
@@ -65,15 +82,33 @@ PUBLIC void vm_init(void)
for (p= 0; p < I386_VM_DIR_ENTRIES; p++)
{
phys_mem= vm_pt_base + p*PAGE_SIZE;
phys_mem= vm_pt_base + p*I386_PAGE_SIZE;
entry= phys_mem | I386_VM_USER | I386_VM_WRITE |
I386_VM_PRESENT;
if (phys_mem >= vm_pt_base + pt_size)
entry= 0;
phys_put32(vm_dir_base + p*I386_VM_PT_ENT_SIZE, entry);
}
/* Set this cr3 in all currently running processes for
* future context switches.
*/
for (rp=BEG_PROC_ADDR; rp<END_PROC_ADDR; rp++) {
u32_t mycr3;
if(isemptyp(rp)) continue;
rp->p_seg.p_cr3 = vm_dir_base;
}
kernel_cr3 = vm_dir_base;
/* Set this cr3 now (not active until paging enabled). */
vm_set_cr3(vm_dir_base);
/* Actually enable paging (activating cr3 load above). */
level0(vm_enable_paging);
/* Don't do this init in the future. */
vm_running = 1;
}
PRIVATE void phys_put32(addr, value)
@@ -113,50 +148,6 @@ PRIVATE void vm_enable_paging(void)
write_cr0(cr0 | I386_CR0_PG);
}
PUBLIC void vm_map_range(base, size, offset)
u32_t base;
u32_t size;
u32_t offset;
{
u32_t curr_pt, curr_pt_addr, entry;
int dir_ent, pt_ent;
if (base % PAGE_SIZE != 0)
panic("map_range: bad base", base);
if (size % PAGE_SIZE != 0)
panic("map_range: bad size", size);
if (offset % PAGE_SIZE != 0)
panic("map_range: bad offset", offset);
curr_pt= -1;
curr_pt_addr= 0;
while (size != 0)
{
dir_ent= (base >> I386_VM_DIR_ENT_SHIFT);
pt_ent= (base >> I386_VM_PT_ENT_SHIFT) & I386_VM_PT_ENT_MASK;
if (dir_ent != curr_pt)
{
/* Get address of page table */
curr_pt= dir_ent;
curr_pt_addr= phys_get32(vm_cr3 +
dir_ent * I386_VM_PT_ENT_SIZE);
curr_pt_addr &= I386_VM_ADDR_MASK;
}
entry= offset | I386_VM_USER | I386_VM_WRITE |
I386_VM_PRESENT;
#if 0 /* Do we need this for memory mapped I/O? */
entry |= I386_VM_PCD | I386_VM_PWT;
#endif
phys_put32(curr_pt_addr + pt_ent * I386_VM_PT_ENT_SIZE, entry);
offset += PAGE_SIZE;
base += PAGE_SIZE;
size -= PAGE_SIZE;
}
/* reload root of page table. */
vm_set_cr3(vm_cr3);
}
PUBLIC vir_bytes alloc_remote_segment(u32_t *selector,
segframe_t *segments, int index, phys_bytes phys, vir_bytes size,
int priv)
@@ -188,6 +179,10 @@ PUBLIC phys_bytes umap_remote(struct proc* rp, int seg,
/* Calculate the physical memory address for a given virtual address. */
struct far_mem *fm;
#if 0
if(rp->p_misc_flags & MF_FULLVM) return 0;
#endif
if (bytes <= 0) return( (phys_bytes) 0);
if (seg < 0 || seg >= NR_REMOTE_SEGS) return( (phys_bytes) 0);
@@ -212,6 +207,9 @@ vir_bytes bytes; /* # of bytes to be copied */
phys_bytes pa; /* intermediate variables as phys_bytes */
phys_bytes seg_base;
if(seg != T && seg != D && seg != S)
minix_panic("umap_local: wrong seg", seg);
if (bytes <= 0) return( (phys_bytes) 0);
if (vir_addr + bytes <= vir_addr) return 0; /* overflow */
vc = (vir_addr + bytes - 1) >> CLICK_SHIFT; /* last click of data */
@@ -232,3 +230,569 @@ vir_bytes bytes; /* # of bytes to be copied */
return(seg_base + pa);
}
/*===========================================================================*
* umap_virtual *
*===========================================================================*/
PUBLIC phys_bytes umap_virtual(rp, seg, vir_addr, bytes)
register struct proc *rp; /* pointer to proc table entry for process */
int seg; /* T, D, or S segment */
vir_bytes vir_addr; /* virtual address in bytes within the seg */
vir_bytes bytes; /* # of bytes to be copied */
{
vir_bytes linear;
u32_t phys = 0;
if(seg == MEM_GRANT) {
phys = umap_grant(rp, vir_addr, bytes);
} else {
if(!(linear = umap_local(rp, seg, vir_addr, bytes))) {
kprintf("SYSTEM:umap_virtual: umap_local failed\n");
phys = 0;
} else {
if(vm_lookup(rp, linear, &phys, NULL) != OK) {
kprintf("SYSTEM:umap_virtual: vm_lookup of %s: seg 0x%lx: 0x%lx failed\n", rp->p_name, seg, vir_addr);
phys = 0;
}
if(phys == 0)
minix_panic("vm_lookup returned phys", phys);
}
}
if(phys == 0) {
kprintf("SYSTEM:umap_virtual: lookup failed\n");
return 0;
}
/* Now make sure addresses are contiguous in physical memory
* so that the umap makes sense.
*/
if(bytes > 0 && !vm_contiguous(rp, linear, bytes)) {
kprintf("umap_virtual: %s: %d at 0x%lx (vir 0x%lx) not contiguous\n",
rp->p_name, bytes, linear, vir_addr);
return 0;
}
/* phys must be larger than 0 (or the caller will think the call
* failed), and address must not cross a page boundary.
*/
vmassert(phys);
return phys;
}
/*===========================================================================*
* vm_lookup *
*===========================================================================*/
PUBLIC int vm_lookup(struct proc *proc, vir_bytes virtual, vir_bytes *physical, u32_t *ptent)
{
u32_t *root, *pt;
int pde, pte;
u32_t pde_v, pte_v;
vmassert(proc);
vmassert(physical);
vmassert(!(proc->p_rts_flags & SLOT_FREE));
/* Retrieve page directory entry. */
root = (u32_t *) proc->p_seg.p_cr3;
vmassert(!((u32_t) root % I386_PAGE_SIZE));
pde = I386_VM_PDE(virtual);
vmassert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & I386_VM_PRESENT)) {
#if 0
kprintf("vm_lookup: %d:%s:0x%lx: cr3 0x%lx: pde %d not present\n",
proc->p_endpoint, proc->p_name, virtual, root, pde);
kprintf("kernel stack: ");
util_stacktrace();
#endif
return EFAULT;
}
/* Retrieve page table entry. */
pt = (u32_t *) I386_VM_PFA(pde_v);
vmassert(!((u32_t) pt % I386_PAGE_SIZE));
pte = I386_VM_PTE(virtual);
vmassert(pte >= 0 && pte < I386_VM_PT_ENTRIES);
pte_v = phys_get32((u32_t) (pt + pte));
if(!(pte_v & I386_VM_PRESENT)) {
#if 0
kprintf("vm_lookup: %d:%s:0x%lx: cr3 %lx: pde %d: pte %d not present\n",
proc->p_endpoint, proc->p_name, virtual, root, pde, pte);
kprintf("kernel stack: ");
util_stacktrace();
#endif
return EFAULT;
}
if(ptent) *ptent = pte_v;
/* Actual address now known; retrieve it and add page offset. */
*physical = I386_VM_PFA(pte_v);
*physical += virtual % I386_PAGE_SIZE;
return OK;
}
/* From virtual address v in process p,
* lookup physical address and assign it to d.
* If p is NULL, assume it's already a physical address.
*/
#define LOOKUP(d, p, v, flagsp) { \
int r; \
if(!(p)) { (d) = (v); } \
else { \
if((r=vm_lookup((p), (v), &(d), flagsp)) != OK) { \
kprintf("vm_copy: lookup failed of 0x%lx in %d (%s)\n"\
"kernel stacktrace: ", (v), (p)->p_endpoint, \
(p)->p_name); \
util_stacktrace(); \
return r; \
} } }
/*===========================================================================*
* vm_copy *
*===========================================================================*/
int vm_copy(vir_bytes src, struct proc *srcproc,
vir_bytes dst, struct proc *dstproc, phys_bytes bytes)
{
#define WRAPS(v) (ULONG_MAX - (v) <= bytes)
if(WRAPS(src) || WRAPS(dst))
minix_panic("vm_copy: linear address wraps", NO_NUM);
while(bytes > 0) {
u32_t n, flags;
phys_bytes p_src, p_dst;
#define PAGEREMAIN(v) (I386_PAGE_SIZE - ((v) % I386_PAGE_SIZE))
/* We can copy this number of bytes without
* crossing a page boundary, but don't copy more
* than asked.
*/
n = MIN(PAGEREMAIN(src), PAGEREMAIN(dst));
n = MIN(n, bytes);
vmassert(n > 0);
vmassert(n <= I386_PAGE_SIZE);
/* Convert both virtual addresses to physical and do
* copy.
*/
LOOKUP(p_src, srcproc, src, NULL);
LOOKUP(p_dst, dstproc, dst, &flags);
if(!(flags & I386_VM_WRITE)) {
kprintf("vm_copy: copying to nonwritable page\n");
kprintf("kernel stack: ");
util_stacktrace();
return EFAULT;
}
phys_copy(p_src, p_dst, n);
/* Book number of bytes copied. */
vmassert(bytes >= n);
bytes -= n;
src += n;
dst += n;
}
return OK;
}
/*===========================================================================*
* vm_contiguous *
*===========================================================================*/
PUBLIC int vm_contiguous(struct proc *targetproc, u32_t vir_buf, size_t bytes)
{
int first = 1, r, boundaries = 0;
u32_t prev_phys, po;
u32_t prev_vir;
vmassert(targetproc);
vmassert(bytes > 0);
vmassert(vm_running);
/* Start and end at page boundary to make logic simpler. */
po = vir_buf % I386_PAGE_SIZE;
if(po > 0) {
bytes += po;
vir_buf -= po;
}
po = (vir_buf + bytes) % I386_PAGE_SIZE;
if(po > 0)
bytes += I386_PAGE_SIZE - po;
/* Keep going as long as we cross a page boundary. */
while(bytes > 0) {
u32_t phys;
if((r=vm_lookup(targetproc, vir_buf, &phys, NULL)) != OK) {
kprintf("vm_contiguous: vm_lookup failed, %d\n", r);
kprintf("kernel stack: ");
util_stacktrace();
return 0;
}
if(!first) {
if(prev_phys+I386_PAGE_SIZE != phys) {
kprintf("vm_contiguous: no (0x%lx, 0x%lx)\n",
prev_phys, phys);
kprintf("kernel stack: ");
util_stacktrace();
return 0;
}
}
first = 0;
prev_phys = phys;
prev_vir = vir_buf;
vir_buf += I386_PAGE_SIZE;
bytes -= I386_PAGE_SIZE;
boundaries++;
}
if(verbose_vm)
kprintf("vm_contiguous: yes (%d boundaries tested)\n",
boundaries);
return 1;
}
int vm_checkrange_verbose = 0;
/*===========================================================================*
* vm_checkrange *
*===========================================================================*/
PUBLIC int vm_checkrange(struct proc *caller, struct proc *target,
vir_bytes vir, vir_bytes bytes, int wrfl, int checkonly)
{
u32_t flags, po, v;
int r;
vmassert(vm_running);
/* If caller has had a reply to this request, return it. */
if(RTS_ISSET(caller, VMREQUEST)) {
if(caller->p_vmrequest.who == target->p_endpoint) {
if(caller->p_vmrequest.vmresult == VMSUSPEND)
minix_panic("check sees VMSUSPEND?", NO_NUM);
RTS_LOCK_UNSET(caller, VMREQUEST);
#if 0
kprintf("SYSTEM: vm_checkrange: returning vmresult %d\n",
caller->p_vmrequest.vmresult);
#endif
return caller->p_vmrequest.vmresult;
} else {
#if 0
kprintf("SYSTEM: vm_checkrange: caller has a request for %d, "
"but our target is %d\n",
caller->p_vmrequest.who, target->p_endpoint);
#endif
}
}
po = vir % I386_PAGE_SIZE;
if(po > 0) {
vir -= po;
bytes += po;
}
vmassert(target);
vmassert(bytes > 0);
for(v = vir; v < vir + bytes; v+= I386_PAGE_SIZE) {
u32_t phys;
/* If page exists and it's writable if desired, we're OK
* for this page.
*/
if(vm_lookup(target, v, &phys, &flags) == OK &&
!(wrfl && !(flags & I386_VM_WRITE))) {
if(vm_checkrange_verbose) {
#if 0
kprintf("SYSTEM: checkrange:%s:%d: 0x%lx: write 0x%lx, flags 0x%lx, phys 0x%lx, OK\n",
target->p_name, target->p_endpoint, v, wrfl, flags, phys);
#endif
}
continue;
}
if(vm_checkrange_verbose) {
kprintf("SYSTEM: checkrange:%s:%d: 0x%lx: write 0x%lx, flags 0x%lx, phys 0x%lx, NOT OK\n",
target->p_name, target->p_endpoint, v, wrfl, flags, phys);
}
if(checkonly)
return VMSUSPEND;
/* This range is not OK for this process. Set parameters
* of the request and notify VM about the pending request.
*/
if(RTS_ISSET(caller, VMREQUEST))
minix_panic("VMREQUEST already set", caller->p_endpoint);
RTS_LOCK_SET(caller, VMREQUEST);
/* Set parameters in caller. */
caller->p_vmrequest.writeflag = wrfl;
caller->p_vmrequest.start = vir;
caller->p_vmrequest.length = bytes;
caller->p_vmrequest.who = target->p_endpoint;
/* Set caller in target. */
target->p_vmrequest.requestor = caller;
/* Connect caller on vmrequest wait queue. */
caller->p_vmrequest.nextrequestor = vmrequest;
vmrequest = caller;
soft_notify(VM_PROC_NR);
#if 0
kprintf("SYSTEM: vm_checkrange: range bad for "
"target %s:0x%lx-0x%lx, caller %s\n",
target->p_name, vir, vir+bytes, caller->p_name);
kprintf("vm_checkrange kernel trace: ");
util_stacktrace();
kprintf("target trace: ");
proc_stacktrace(target);
#endif
if(target->p_endpoint == VM_PROC_NR) {
kprintf("caller trace: ");
proc_stacktrace(caller);
kprintf("target trace: ");
proc_stacktrace(target);
minix_panic("VM ranges should be OK", NO_NUM);
}
return VMSUSPEND;
}
return OK;
}
char *flagstr(u32_t e, int dir)
{
static char str[80];
strcpy(str, "");
#define FLAG(v) do { if(e & (v)) { strcat(str, #v " "); } } while(0)
FLAG(I386_VM_PRESENT);
FLAG(I386_VM_WRITE);
FLAG(I386_VM_USER);
FLAG(I386_VM_PWT);
FLAG(I386_VM_PCD);
if(dir)
FLAG(I386_VM_BIGPAGE); /* Page directory entry only */
else
FLAG(I386_VM_DIRTY); /* Page table entry only */
return str;
}
void vm_pt_print(u32_t *pagetable, u32_t v)
{
int pte, l = 0;
int col = 0;
vmassert(!((u32_t) pagetable % I386_PAGE_SIZE));
for(pte = 0; pte < I386_VM_PT_ENTRIES; pte++) {
u32_t pte_v, pfa;
pte_v = phys_get32((u32_t) (pagetable + pte));
if(!(pte_v & I386_VM_PRESENT))
continue;
pfa = I386_VM_PFA(pte_v);
kprintf("%4d:%08lx:%08lx ",
pte, v + I386_PAGE_SIZE*pte, pfa);
col++;
if(col == 3) { kprintf("\n"); col = 0; }
}
if(col > 0) kprintf("\n");
return;
}
/*===========================================================================*
* vm_print *
*===========================================================================*/
void vm_print(u32_t *root)
{
int pde;
vmassert(!((u32_t) root % I386_PAGE_SIZE));
for(pde = 0; pde < I386_VM_DIR_ENTRIES; pde++) {
u32_t pde_v;
u32_t *pte_a;
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & I386_VM_PRESENT))
continue;
pte_a = (u32_t *) I386_VM_PFA(pde_v);
kprintf("%4d: pt %08lx %s\n",
pde, pte_a, flagstr(pde_v, 1));
vm_pt_print(pte_a, pde * I386_VM_PT_ENTRIES * I386_PAGE_SIZE);
}
return;
}
/*===========================================================================*
* virtual_copy_f *
*===========================================================================*/
PUBLIC int virtual_copy_f(src_addr, dst_addr, bytes, vmcheck)
struct vir_addr *src_addr; /* source virtual address */
struct vir_addr *dst_addr; /* destination virtual address */
vir_bytes bytes; /* # of bytes to copy */
int vmcheck; /* if nonzero, can return VMSUSPEND */
{
/* Copy bytes from virtual address src_addr to virtual address dst_addr.
* Virtual addresses can be in ABS, LOCAL_SEG, REMOTE_SEG, or BIOS_SEG.
*/
struct vir_addr *vir_addr[2]; /* virtual source and destination address */
phys_bytes phys_addr[2]; /* absolute source and destination */
int seg_index;
int i, r;
struct proc *procs[2];
/* Check copy count. */
if (bytes <= 0) return(EDOM);
/* Do some more checks and map virtual addresses to physical addresses. */
vir_addr[_SRC_] = src_addr;
vir_addr[_DST_] = dst_addr;
for (i=_SRC_; i<=_DST_; i++) {
int proc_nr, type;
struct proc *p;
type = vir_addr[i]->segment & SEGMENT_TYPE;
if((type != PHYS_SEG && type != BIOS_SEG) &&
isokendpt(vir_addr[i]->proc_nr_e, &proc_nr))
p = proc_addr(proc_nr);
else
p = NULL;
procs[i] = p;
/* Get physical address. */
switch(type) {
case LOCAL_SEG:
case LOCAL_VM_SEG:
if(!p) return EDEADSRCDST;
seg_index = vir_addr[i]->segment & SEGMENT_INDEX;
if(type == LOCAL_SEG)
phys_addr[i] = umap_local(p, seg_index, vir_addr[i]->offset,
bytes);
else
phys_addr[i] = umap_virtual(p, seg_index, vir_addr[i]->offset,
bytes);
if(phys_addr[i] == 0) {
kprintf("virtual_copy: map 0x%x failed for %s seg %d, "
"offset %lx, len %d, i %d\n",
type, p->p_name, seg_index, vir_addr[i]->offset,
bytes, i);
}
break;
case REMOTE_SEG:
if(!p) return EDEADSRCDST;
seg_index = vir_addr[i]->segment & SEGMENT_INDEX;
phys_addr[i] = umap_remote(p, seg_index, vir_addr[i]->offset, bytes);
break;
#if _MINIX_CHIP == _CHIP_INTEL
case BIOS_SEG:
phys_addr[i] = umap_bios(vir_addr[i]->offset, bytes );
break;
#endif
case PHYS_SEG:
phys_addr[i] = vir_addr[i]->offset;
break;
case GRANT_SEG:
phys_addr[i] = umap_grant(p, vir_addr[i]->offset, bytes);
break;
default:
kprintf("virtual_copy: strange type 0x%x\n", type);
return(EINVAL);
}
/* Check if mapping succeeded. */
if (phys_addr[i] <= 0 && vir_addr[i]->segment != PHYS_SEG) {
kprintf("virtual_copy EFAULT\n");
return(EFAULT);
}
}
if(vmcheck && procs[_SRC_])
CHECKRANGE_OR_SUSPEND(procs[_SRC_], phys_addr[_SRC_], bytes, 0);
if(vmcheck && procs[_DST_])
CHECKRANGE_OR_SUSPEND(procs[_DST_], phys_addr[_DST_], bytes, 1);
/* Now copy bytes between physical addresseses. */
if(!vm_running || (procs[_SRC_] == NULL && procs[_DST_] == NULL)) {
/* Without vm, address ranges actually are physical. */
phys_copy(phys_addr[_SRC_], phys_addr[_DST_], (phys_bytes) bytes);
r = OK;
} else {
/* With vm, addresses need further interpretation. */
r = vm_copy(phys_addr[_SRC_], procs[_SRC_],
phys_addr[_DST_], procs[_DST_], (phys_bytes) bytes);
if(r != OK) {
kprintf("vm_copy: %lx to %lx failed\n",
phys_addr[_SRC_],phys_addr[_DST_]);
}
}
return(r);
}
/*===========================================================================*
* data_copy *
*===========================================================================*/
PUBLIC int data_copy(
endpoint_t from_proc, vir_bytes from_addr,
endpoint_t to_proc, vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.segment = dst.segment = D;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
return virtual_copy(&src, &dst, bytes);
}
/*===========================================================================*
* arch_pre_exec *
*===========================================================================*/
PUBLIC int arch_pre_exec(struct proc *pr, u32_t ip, u32_t sp)
{
/* wipe extra LDT entries, set program counter, and stack pointer. */
memset(pr->p_seg.p_ldt + EXTRA_LDT_INDEX, 0,
sizeof(pr->p_seg.p_ldt[0]) * (LDT_SIZE - EXTRA_LDT_INDEX));
pr->p_reg.pc = ip;
pr->p_reg.sp = sp;
}
/*===========================================================================*
* arch_umap *
*===========================================================================*/
PUBLIC int arch_umap(struct proc *pr, vir_bytes offset, vir_bytes count,
int seg, phys_bytes *addr)
{
switch(seg) {
case BIOS_SEG:
*addr = umap_bios(offset, count);
return OK;
}
/* This must be EINVAL; the umap fallback function in
* lib/syslib/alloc_util.c depends on it to detect an
* older kernel (as opposed to mapping error).
*/
return EINVAL;
}