Imbus/xv6-riscv-kernel
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Make AP processors boot using bootpgdir

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Remove device mapping from bootpgdir
Remove unnecessary vmenable
Set CPUS back to 2 in Makefile
Passes all usertests
This commit is contained in:
Frans Kaashoek 2011-08-11 12:25:10 -04:00
parent 673b739d31
commit bd71a45046
5 changed files with 42 additions and 65 deletions
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30
vm.c
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@ -8,7 +8,7 @@
#include "elf.h"
extern char data[]; // defined in data.S
static pde_t *kpgdir; // for use in scheduler()
pde_t *kpgdir; // for use in scheduler()
struct segdesc gdt[NSEGS];
// Set up CPU's kernel segment descriptors.
@ -40,7 +40,7 @@ seginit(void)
}
// Return the address of the PTE in page table pgdir
// that corresponds to linear address va. If create!=0,
// that corresponds to linear address va. If alloc!=0,
// create any required page table pages.
static pte_t *
walkpgdir(pde_t *pgdir, const void *va, char* (*alloc)(void))
@ -102,8 +102,8 @@ mappages(pde_t *pgdir, void *la, uint size, uint pa, int perm, char* (*alloc)(vo
// setupkvm() and exec() set up every page table like this:
// 0..USERTOP : user memory (text, data, stack, heap), mapped to some unused phys mem
// KERNBASE..KERNBASE+1M: mapped to 0..1M
// KERNBASE+1M..KERNBASE+end : mapped to 1M..end
// KERNBASE+end..KERBASE+PHYSTOP : mapped to end..PHYSTOP (free memory)
// KERNBASE+1M..KERNBASE+end : mapped to 1M..end (mapped without write permission)
// KERNBASE+end..KERBASE+PHYSTOP : mapped to end..PHYSTOP (rw data + free memory)
// 0xfe000000..0 : mapped direct (devices such as ioapic)
//
// The kernel allocates memory for its heap and for user memory
@ -150,28 +150,6 @@ kvmalloc(void)
switchkvm();
}
// Turn on paging.
void
vmenable(void)
{
uint cr0;
switchkvm(); // load kpgdir into cr3
cr0 = rcr0();
cr0 |= CR0_PG;
lcr0(cr0);
struct cpu *c = &cpus[0];
lgdt((void *)v2p((void *)(c->gdt)), sizeof(c->gdt));
loadgs(SEG_KCPU << 3);
loadfs(SEG_KDATA << 3);
loades(SEG_KDATA << 3);
loadds(SEG_KDATA << 3);
loadss(SEG_KDATA << 3);
__asm volatile("ljmp %0,$1f\n 1:\n" :: "i" (SEG_KCODE << 3)); // reload cs
}
// Switch h/w page table register to the kernel-only page table,
// for when no process is running.
void