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| author | Robert Morris <rtm@csail.mit.edu> | 2019-05-31 09:45:59 -0400 |
|---|---|---|
| committer | Robert Morris <rtm@csail.mit.edu> | 2019-05-31 09:45:59 -0400 |
| commit | 2ec1959fd1016a18ef3b2d154ce7076be8f237e4 (patch) | |
| tree | 1aa75252085964283b3a2c735771f4da02346517 /memlayout.h | |
| parent | 0f90388c893d1924e89e2e4d2187eda0004e9d73 (diff) | |
| download | xv6-labs-2ec1959fd1016a18ef3b2d154ce7076be8f237e4.tar.gz xv6-labs-2ec1959fd1016a18ef3b2d154ce7076be8f237e4.tar.bz2 xv6-labs-2ec1959fd1016a18ef3b2d154ce7076be8f237e4.zip | |
fork/wait/exit work
Diffstat (limited to 'memlayout.h')
| -rw-r--r-- | memlayout.h | 33 |
1 files changed, 21 insertions, 12 deletions
diff --git a/memlayout.h b/memlayout.h index 87818d3..798621e 100644 --- a/memlayout.h +++ b/memlayout.h @@ -1,16 +1,25 @@ -// Memory layout +// Physical memory layout -#define EXTMEM 0x100000 // Start of extended memory -#define PHYSTOP 0xE000000 // Top physical memory -#define DEVSPACE 0xFE000000 // Other devices are top of 32-bit address space -#define DEVSPACETOP 0x100000000 +// qemu -machine virt is set up like this: +// 00001000 -- boot ROM, provided by qemu +// 10000000 -- uart0 registers +// 80000000 -- boot ROM jumps here in machine mode +// unused RAM after 80000000. -// Key addresses for address space layout (see kmap in vm.c for layout) -#define KERNBASE 0xFFFFFF0000000000 // First kernel virtual address -#define KERNLINK (KERNBASE+EXTMEM) // Address where kernel is linked +// the kernel uses physical memory thus: +// 80000000 -- entry.S, then kernel text and data +// end -- start of kernel page allocation area +// PHYSTOP -- end RAM used by the kernel -#define V2P(a) (((uint64) (a)) - KERNBASE) -#define P2V(a) ((void *)(((char *) (a)) + KERNBASE)) +// registers start here in physical memory. +#define UART0 0x10000000L -#define V2P_WO(x) ((x) - KERNBASE) // same as V2P, but without casts -#define P2V_WO(x) ((x) + KERNBASE) // same as P2V, but without casts +// the kernel expects there to be RAM +// for use by the kernel and user pages +// from physical address 0x80000000 to PHYSTOP. +#define KERNBASE 0x80000000L +#define PHYSTOP (KERNBASE + 64*1024*1024) + +// map the trampoline page to the highest address, +// in both user and kernel space. +#define TRAMPOLINE (MAXVA - PGSIZE) |