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2019-06-11separate source into kernel/ user/ mkfs/Robert Morris1-149/+0
2019-06-05clean up -WallRobert Morris1-1/+0
2019-06-04check that arguments aren't more than a page in exec()Robert Morris1-1/+6
2019-06-04fix exec argcRobert Morris1-14/+14
2019-06-04support read() and write() bigger than one pageRobert Morris1-3/+5
2019-06-01first shell prints $ prompt, though no console input yetRobert Morris1-2/+0
2019-05-31exec compiles but argstr() doesn't work yetRobert Morris1-24/+50
2019-05-31fork/wait/exit workRobert Morris1-11/+11
2018-10-09Separate system call path from trap path. Passes usertests on 1 and 2 cpus.Frans Kaashoek1-5/+4
2018-09-23Checkpoint port of xv6 to x86-64. Passed usertests on 2 processors a few times.Frans Kaashoek1-12/+18
The x86-64 doesn't just add two levels to page tables to support 64 bit addresses, but is a different processor. For example, calling conventions, system calls, and segmentation are different from 32-bit x86. Segmentation is basically gone, but gs/fs in combination with MSRs can be used to hold a per-core pointer. In general, x86-64 is more straightforward than 32-bit x86. The port uses code from sv6 and the xv6 "rsc-amd64" branch. A summary of the changes is as follows: - Booting: switch to grub instead of xv6's bootloader (pass -kernel to qemu), because xv6's boot loader doesn't understand 64bit ELF files. And, we don't care anymore about booting. - Makefile: use -m64 instead of -m32 flag for gcc, delete boot loader, xv6.img, bochs, and memfs. For now dont' use -O2, since usertests with -O2 is bigger than MAXFILE! - Update gdb.tmpl to be for i386 or x86-64 - Console/printf: use stdarg.h and treat 64-bit addresses different from ints (32-bit) - Update elfhdr to be 64 bit - entry.S/entryother.S: add code to switch to 64-bit mode: build a simple page table in 32-bit mode before switching to 64-bit mode, share code for entering boot processor and APs, and tweak boot gdt. The boot gdt is the gdt that the kernel proper also uses. (In 64-bit mode, the gdt/segmentation and task state mostly disappear.) - exec.c: fix passing argv (64-bit now instead of 32-bit). - initcode.c: use syscall instead of int. - kernel.ld: load kernel very high, in top terabyte. 64 bits is a lot of address space! - proc.c: initial return is through new syscall path instead of trapret. - proc.h: update struct cpu to have some scratch space since syscall saves less state than int, update struct context to reflect x86-64 calling conventions. - swtch: simplify for x86-64 calling conventions. - syscall: add fetcharg to handle x86-64 calling convetions (6 arguments are passed through registers), and fetchaddr to read a 64-bit value from user space. - sysfile: update to handle pointers from user space (e.g., sys_exec), which are 64 bits. - trap.c: no special trap vector for sys calls, because x86-64 has a different plan for system calls. - trapasm: one plan for syscalls and one plan for traps (interrupt and exceptions). On x86-64, the kernel is responsible for switching user/kernel stacks. To do, xv6 keeps some scratch space in the cpu structure, and uses MSR GS_KERN_BASE to point to the core's cpu structure (using swapgs). - types.h: add uint64, and change pde_t to uint64 - usertests: exit() when fork fails, which helped in tracking down one of the bugs in the switch from 32-bit to 64-bit - vectors: update to make them 64 bits - vm.c: use bootgdt in kernel too, program MSRs for syscalls and core-local state (for swapgs), walk 4 levels in walkpgdir, add DEVSPACETOP, use task segment to set kernel stack for interrupts (but simpler than in 32-bit mode), add an extra argument to freevm (size of user part of address space) to avoid checking all entries till KERNBASE (there are MANY TB before the top 1TB). - x86: update trapframe to have 64-bit entries, which is what the processor pushes on syscalls and traps. simplify lgdt and lidt, using struct desctr, which needs the gcc directives packed and aligned. TODO: - use int32 instead of int? - simplify curproc(). xv6 has per-cpu state again, but this time it must have it. - avoid repetition in walkpgdir - fix validateint() in usertests.c - fix bugs (e.g., observed one a case of entering kernel with invalid gs or proc
2017-01-31Read curproc from cpu structure, but be careful because after a schedule eventFrans Kaashoek1-7/+8
myproc() points to a different thread. myproc(); sched(); myproc(); // this proc maybe different than the one before sched Thus, in a function that operates on one thread better to retrieve the current process once at the start of the function.
2017-01-31Start of an experiment to remove the use of gs for cpu local variables.Frans Kaashoek1-7/+8
2017-01-30Fix unsigned conversion bug.Peter H. Froehlich1-1/+1
Since readi() returns -1 for errors, checking with < against an unsigned value is inadvisable. Checking with != works as intended however.
2016-09-14Delete two left-over print statementsFrans Kaashoek1-2/+0
2016-09-11Straight replacement of B_BUSY with a sleeping lock.Frans Kaashoek1-0/+3
2016-08-25add check for wrapping of address + size in exec()MikeCAT1-0/+2
2016-08-25add alignment check of virtual address to exec()MikeCAT1-0/+2
2014-08-27a start at concurrent FS system callsRobert Morris1-4/+4
2014-08-04every iput() and namei() must be inside a transactionRobert Morris1-2/+8
2012-08-22Remove unused argument to setupkvm (thanks to Peter Froehlich)Frans Kaashoek1-1/+1
2011-09-03I can't do math; fix bug introduced in 5a9761Austin Clements1-1/+1
2011-09-02Fit exec on a page. AgainAustin Clements1-5/+2
2011-09-02clear_pte_u -> clearpteuAustin Clements1-1/+1
2011-09-01inaccessible page under the user stack page, to help exec deal w/ too-large argsRobert Morris1-3/+6
2011-08-17Make elf proghdr fields match what objdump printsFrans Kaashoek1-2/+2
2011-08-09Use static page table for boot, mapping first 4Mbyte; no more segment trickFrans Kaashoek1-1/+1
Allocate proper kernel page table immediately in main using boot allocator Remove pginit Simplify address space layout a tiny bit More to come (e.g., superpages to simplify static table)
2011-07-29Map kernel highFrans Kaashoek1-0/+1
Very important to give qemu memory through PHYSTOP :(
2011-02-19xv6: formatting, cleanup, rev5 (take 2)Russ Cox1-44/+18
2011-01-11make new code like old codeRuss Cox1-12/+12
Variable declarations at top of function, separate from initialization. Use == 0 instead of ! for checking pointers. Consistent spacing around {, *, casts. Declare 0-parameter functions as (void) not (). Integer valued functions return -1 on failure, 0 on success.
2010-09-29even more fabulous execRobert Morris1-19/+8
2010-09-27check exec() arg lengthRobert Morris1-3/+8
fix double iunlockput
2010-09-27copyout() copies data to a va in a pagetable, for exec() &cRobert Morris1-35/+58
usertest that passes too many arguments, break exec
2010-09-19my comment is wrong, exec handles BSS fineRobert Morris1-3/+0
2010-09-19exec questionsRobert Morris1-0/+6
2010-09-02Simplify allocuvm/deallocuvm to operate in a contiguous memory model. This ↵Austin Clements1-15/+11
makes their interface match up better with proc->sz and also simplifies the callers (it even gets the main body of exec on one page).
2010-09-01Remove the stack guard page. Processes are now contiguous from 0 to ↵Austin Clements1-1/+0
proc->sz, which means our syscall argument validation is correct. Add a pointer validation test and remove the stack test, which tested for the guard page.
2010-09-01Tab policeAustin Clements1-5/+5
2010-08-06fix corner cases in exec of ELFRobert Morris1-2/+5
put an invalid page below the stack have fork() handle invalid pages
2010-07-23a few nitsFrans Kaashoek1-1/+1
passes all tests on two-processor smp
2010-07-23Checkpoint page-table version for SMPFrans Kaashoek1-5/+1
Includes code for TLB shootdown (which actually seems unnecessary for xv6)
2010-07-02Initial version of single-cpu xv6 with page tablesFrans Kaashoek1-50/+40
2009-08-30assorted fixes:Russ Cox1-7/+7
* rename c/cp to cpu/proc * rename cpu.context to cpu.scheduler * fix some comments * formatting for printout
2009-08-08shuffle and tweak for formatting.Russ Cox1-2/+4
pdf has very good page breaks now. would be a good copy for fall 2009.
2009-07-13exec tweaksRuss Cox1-6/+11
2009-05-31exec sanity checkrsc1-1/+1
2009-05-31Some proc cleanup, moving some of copyproc into allocproc.rsc1-1/+1
Also, an experiment: use "thread-local" storage for c and cp instead of the #define macro for curproc[cpu()].
2007-08-30oops - broke arg countingrsc1-1/+1
2007-08-28oopsrsc1-1/+1
2007-08-27delete unnecessary #include linesrsc1-1/+0
2007-08-27Edit exec.rsc1-77/+59
Do not commit to new memory image until nothing can go wrong, avoiding bad2 case. Be sure to allocate enough stack space for argv. Load executable before initializing stack, to keep ELF loops together. Make argv loop clearer.