This is the mail archive of the gdb-patches@sourceware.org mailing list for the GDB project.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |
Other format: | [Raw text] |
On Tuesday, March 01, 2011 16:19:25 Pedro Alves wrote: > On Tuesday 22 February 2011 20:26:44, Mike Frysinger wrote: > > --- /dev/null > > +++ b/sim/bfin/linux-fixed-code.h > > @@ -0,0 +1,23 @@ > > +/* DO NOT EDIT: Autogenerated. */ > > +/* Fixed code region of Linux userspace starting at 0x400. Last > > produced + from Linux-2.6.37 (not that the fixed code region changes > > often). */ +static const unsigned char bfin_linux_fixed_code[] = { > > +0x28, 0xe1, 0xad, 0x00, 0xa0, 0x00, 0x00, 0x20, > > (...) > > > +0xa4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, > > +}; > > Now this kernel code in question was probably (haven't > checked) largely written by ADI, and as such ADI could > probably contribute a standalone version of its source > to the FSF under GPLv3, along with some script or makefile > that compiles it with a bfin-gcc and then generates > the blob array. Or you could write simple dumb > replacement implementations of the interface instead? this code was written purely by ADI employees (2 or 3 of them to be exact), is written in pure Blackfin assembly, and we've explicitly licensed this file under GPLv2 or later. so i dont think this is an issue. it is not used by the kernel at all ... the code is placed in a fixed location for userspace binaries to call and is defined as part of the Blackfin ABI. see below. -mike /* * This file contains sequences of code that will be copied to a * fixed location, defined in <asm/fixed_code.h>. The interrupt * handlers ensure that these sequences appear to be atomic when * executed from userspace. * These are aligned to 16 bytes, so that we have some space to replace * these sequences with something else (e.g. kernel traps if we ever do * BF561 SMP). * * Copyright 2007-2008 Analog Devices Inc. * * Licensed under the GPL-2 or later. */ #include <linux/linkage.h> #include <linux/init.h> #include <linux/unistd.h> #include <asm/entry.h> __INIT ENTRY(_fixed_code_start) .align 16 ENTRY(_sigreturn_stub) P0 = __NR_rt_sigreturn; EXCPT 0; /* Speculative execution paranoia. */ 0: JUMP.S 0b; ENDPROC (_sigreturn_stub) .align 16 /* * Atomic swap, 8 bit. * Inputs: P0: memory address to use * R1: value to store * Output: R0: old contents of the memory address, zero extended. */ ENTRY(_atomic_xchg32) R0 = [P0]; [P0] = R1; rts; ENDPROC (_atomic_xchg32) .align 16 /* * Compare and swap, 32 bit. * Inputs: P0: memory address to use * R1: compare value * R2: new value to store * The new value is stored if the contents of the memory * address is equal to the compare value. * Output: R0: old contents of the memory address. */ ENTRY(_atomic_cas32) R0 = [P0]; CC = R0 == R1; IF !CC JUMP 1f; [P0] = R2; 1: rts; ENDPROC (_atomic_cas32) .align 16 /* * Atomic add, 32 bit. * Inputs: P0: memory address to use * R0: value to add * Outputs: R0: new contents of the memory address. * R1: previous contents of the memory address. */ ENTRY(_atomic_add32) R1 = [P0]; R0 = R1 + R0; [P0] = R0; rts; ENDPROC (_atomic_add32) .align 16 /* * Atomic sub, 32 bit. * Inputs: P0: memory address to use * R0: value to subtract * Outputs: R0: new contents of the memory address. * R1: previous contents of the memory address. */ ENTRY(_atomic_sub32) R1 = [P0]; R0 = R1 - R0; [P0] = R0; rts; ENDPROC (_atomic_sub32) .align 16 /* * Atomic ior, 32 bit. * Inputs: P0: memory address to use * R0: value to ior * Outputs: R0: new contents of the memory address. * R1: previous contents of the memory address. */ ENTRY(_atomic_ior32) R1 = [P0]; R0 = R1 | R0; [P0] = R0; rts; ENDPROC (_atomic_ior32) .align 16 /* * Atomic and, 32 bit. * Inputs: P0: memory address to use * R0: value to and * Outputs: R0: new contents of the memory address. * R1: previous contents of the memory address. */ ENTRY(_atomic_and32) R1 = [P0]; R0 = R1 & R0; [P0] = R0; rts; ENDPROC (_atomic_and32) .align 16 /* * Atomic xor, 32 bit. * Inputs: P0: memory address to use * R0: value to xor * Outputs: R0: new contents of the memory address. * R1: previous contents of the memory address. */ ENTRY(_atomic_xor32) R1 = [P0]; R0 = R1 ^ R0; [P0] = R0; rts; ENDPROC (_atomic_xor32) .align 16 /* * safe_user_instruction * Four NOPS are enough to allow the pipeline to speculativily load * execute anything it wants. After that, things have gone bad, and * we are stuck - so panic. Since we might be in user space, we can't * call panic, so just cause a unhandled exception, this should cause * a dump of the trace buffer so we can tell were we are, and a reboot */ ENTRY(_safe_user_instruction) NOP; NOP; NOP; NOP; EXCPT 0x4; ENDPROC(_safe_user_instruction) ENTRY(_fixed_code_end) __FINIT
Attachment:
signature.asc
Description: This is a digitally signed message part.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |