no more pminit, or ELF header at 0x10000

kinit() knows about end and PHYSTOP
map all of kernel read/write (rather than r/o instructions)
thanks, austin
This commit is contained in:
Robert Morris 2010-08-31 15:39:25 -04:00
parent 880ee18ab1
commit 8d774afb2d
5 changed files with 13 additions and 49 deletions

3
defs.h
View file

@ -62,7 +62,7 @@ void ioapicinit(void);
// kalloc.c
char* kalloc(void);
void kfree(char*);
void kinit(char*,uint);
void kinit();
// kbd.c
void kbdintr(void);
@ -151,7 +151,6 @@ void uartintr(void);
void uartputc(int);
// vm.c
void pminit(void);
void ksegment(void);
void kvmalloc(void);
void vmenable(void);

View file

@ -19,11 +19,13 @@ struct {
// Initialize free list of physical pages.
void
kinit(char *p, uint len)
kinit(void)
{
extern char end[];
initlock(&kmem.lock, "kmem");
char *p1 = (char*)PGROUNDUP((uint)p);
char *p2 = PGROUNDDOWN(p + len);
char *p1 = (char*)PGROUNDUP((uint)end);
char *p2 = PGROUNDDOWN(PHYSTOP);
for( ; p1 < p2; p1 += 4096)
kfree(p1);
}

2
main.c
View file

@ -21,7 +21,7 @@ main(void)
ioapicinit(); // another interrupt controller
consoleinit(); // I/O devices & their interrupts
uartinit(); // serial port
pminit(); // discover how much memory there is
kinit(); // initialize memory allocator
jkstack(); // call mainc() on a properly-allocated stack
}

4
mkfs.c
View file

@ -82,7 +82,7 @@ main(int argc, char *argv[])
usedblocks = ninodes / IPB + 3 + bitblocks;
freeblock = usedblocks;
printf("used %d (bit %d ninode %u) free %u total %d\n", usedblocks,
printf("used %d (bit %d ninode %lu) free %u total %d\n", usedblocks,
bitblocks, ninodes/IPB + 1, freeblock, nblocks+usedblocks);
assert(nblocks + usedblocks == size);
@ -230,7 +230,7 @@ balloc(int used)
for(i = 0; i < used; i++) {
buf[i/8] = buf[i/8] | (0x1 << (i%8));
}
printf("balloc: write bitmap block at sector %u\n", ninodes/IPB + 3);
printf("balloc: write bitmap block at sector %lu\n", ninodes/IPB + 3);
wsect(ninodes / IPB + 3, buf);
}

45
vm.c
View file

@ -17,8 +17,8 @@
// setupkvm() and exec() set up every page table like this:
// 0..640K : user memory (text, data, stack, heap)
// 640K..1M : mapped direct (for IO space)
// 1M..kernend : mapped direct (for the kernel's text and data)
// kernend..PHYSTOP : mapped direct (kernel heap and user pages)
// 1M..end : mapped direct (for the kernel's text and data)
// end..PHYSTOP : mapped direct (kernel heap and user pages)
// 0xfe000000..0 : mapped direct (devices such as ioapic)
//
// The kernel allocates memory for its heap and for user memory
@ -31,12 +31,6 @@
#define USERTOP 0xA0000
static uint kerntext; // Linker starts kernel at 1MB
static uint kerntsz;
static uint kerndata;
static uint kerndsz;
static uint kernend;
static uint freesz;
static pde_t *kpgdir; // for use in scheduler()
// return the address of the PTE in page table pgdir
@ -161,14 +155,8 @@ setupkvm(void)
// Map IO space from 640K to 1Mbyte
if (!mappages(pgdir, (void *)USERTOP, 0x60000, USERTOP, PTE_W))
return 0;
// Map kernel text read-only
if (!mappages(pgdir, (void *) kerntext, kerntsz, kerntext, 0))
return 0;
// Map kernel data read/write
if (!mappages(pgdir, (void *) kerndata, kerndsz, kerndata, PTE_W))
return 0;
// Map dynamically-allocated memory read/write (kernel stacks, user mem)
if (!mappages(pgdir, (void *) kernend, freesz, PADDR(kernend), PTE_W))
// Map kernel and free memory pool
if (!mappages(pgdir, (void *)0x100000, PHYSTOP-0x100000, 0x100000, PTE_W))
return 0;
// Map devices such as ioapic, lapic, ...
if (!mappages(pgdir, (void *)0xFE000000, 0x2000000, 0xFE000000, PTE_W))
@ -333,31 +321,6 @@ copyuvm(pde_t *pgdir, uint sz)
return d;
}
// Gather information about physical memory layout.
// Called once during boot.
// Really should find out how much physical memory
// there is rather than assuming PHYSTOP.
void
pminit(void)
{
extern char end[];
struct proghdr *ph;
struct elfhdr *elf = (struct elfhdr*)0x10000; // scratch space
if (elf->magic != ELF_MAGIC || elf->phnum != 2)
panic("pminit: need a text and data segment\n");
ph = (struct proghdr*)((uchar*)elf + elf->phoff);
kernend = ((uint)end + PGSIZE) & ~(PGSIZE-1);
kerntext = ph[0].va;
kerndata = ph[1].va;
kerntsz = ph[0].memsz;
kerndsz = ph[1].memsz;
freesz = PHYSTOP - kernend;
kinit((char *)kernend, freesz);
}
// Allocate one page table for the machine for the kernel address
// space for scheduler processes.
void