Imbus/xv6-riscv-kernel
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PDF at http://am.lcs.mit.edu/~rsc/xv6.pdf

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Various changes made while offline.

 + bwrite sector argument is redundant; use b->sector.
 + reformatting of files for nicer PDF page breaks
 + distinguish between locked, unlocked inodes in type signatures
 + change FD_FILE to FD_INODE
 + move userinit (nee proc0init) to proc.c
 + move ROOTDEV to param.h
 + always parenthesize sizeof argument
This commit is contained in:
rsc 2007-08-22 06:01:32 +00:00
parent 3dcf889c1b
commit eaea18cb9c
25 changed files with 637 additions and 669 deletions
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61
bootmain.c
View file

@ -25,6 +25,7 @@
// * cmain() in this file takes over,
// reads in the kernel and jumps to it.
//PAGEBREAK!
#include "types.h"
#include "elf.h"
#include "x86.h"
@ -32,7 +33,6 @@
#define SECTSIZE 512
#define ELFHDR ((struct elfhdr*) 0x10000) // scratch space
void readsect(void*, uint);
void readseg(uint, uint, uint);
void
@ -64,8 +64,37 @@ bad:
;
}
void
waitdisk(void)
{
// wait for disk reaady
while((inb(0x1F7) & 0xC0) != 0x40)
;
}
// Read a single sector at offset into dst.
void
readsect(void *dst, uint offset)
{
// wait for disk to be ready
waitdisk();
outb(0x1F2, 1); // count = 1
outb(0x1F3, offset);
outb(0x1F4, offset >> 8);
outb(0x1F5, offset >> 16);
outb(0x1F6, (offset >> 24) | 0xE0);
outb(0x1F7, 0x20); // cmd 0x20 - read sectors
// wait for disk to be ready
waitdisk();
// read a sector
insl(0x1F0, dst, SECTSIZE/4);
}
// Read 'count' bytes at 'offset' from kernel into virtual address 'va'.
// Might copy more than asked
// Might copy more than asked.
void
readseg(uint va, uint count, uint offset)
{
@ -90,31 +119,3 @@ readseg(uint va, uint count, uint offset)
}
}
void
waitdisk(void)
{
// wait for disk reaady
while((inb(0x1F7) & 0xC0) != 0x40)
;
}
void
readsect(void *dst, uint offset)
{
// wait for disk to be ready
waitdisk();
outb(0x1F2, 1); // count = 1
outb(0x1F3, offset);
outb(0x1F4, offset >> 8);
outb(0x1F5, offset >> 16);
outb(0x1F6, (offset >> 24) | 0xE0);
outb(0x1F7, 0x20); // cmd 0x20 - read sectors
// wait for disk to be ready
waitdisk();
// read a sector
insl(0x1F0, dst, SECTSIZE/4);
}