diff options
Diffstat (limited to 'sim/ppc/README')
| -rw-r--r-- | sim/ppc/README | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/sim/ppc/README b/sim/ppc/README new file mode 100644 index 00000000000..ff3fbd2b349 --- /dev/null +++ b/sim/ppc/README @@ -0,0 +1,353 @@ + + + PSIM 1.0.1 - Model of the PowerPC Environments + + + Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + + ---------------------------------------------------------------------- + + +PSIM is a program written in extended ANSI-C that implements an +instruction level simulation of the PowerPC environment. It is freely +available in source code form under the terms of the GNU General +Public License (version 2 or later). + +The PowerPC Architecture is described as having three levels of +compliance: + + UEA - User Environment Architecture + VEA - Virtual Environment Architecture + OEA - Operating Environment Architecture + +PSIM both implements all three levels of the PowerPC and includes (for +each level) a corresponding simulated run-time environment. + +In addition, PSIM, to the execution unit level, models the performance +of most of the current PowerPC implementations (contributed by Michael +Meissner). This detailed performance monitoring (unlike many other +simulators) resulting in only a relatively marginal reduction in the +simulators performance. + + +A description of how to build PSIM is contained in the file: + + ftp://ftp.ci.com.au/pub/psim/INSTALL + or ftp://cambridge.cygnus.com/pub/psim/INSTALL + +while an overview of how to use PSIM is in: + + ftp://ftp.ci.com.au/pub/psim/RUN +or ftp://cambridge.cygnus.com/pub/psim/RUN + +This file is found in: + + ftp://ftp.ci.com.au/pub/psim/README +or ftp://cambridge.cygnus.com/pub/psim/README + + +Thanks goes firstly to: + + Corinthian Engineering Pty Ltd + Cygnus Support + Highland Logic Pty Ltd + +who provided the resources needed for making this software available +on the Internet. + +More importantly I'd like to thank the following individuals who each +contributed in their own unique way: + + Allen Briggs, Bett Koch, David Edelsohn, Gordon Irlam, + Michael Meissner, Bob Mercier, Richard Perini, Dale Rahn, + Richard Stallman, Mitchele Walker + + + Andrew Cagney + Feb, 1995 + + + ---------------------------------------------------------------------- + + + What features does PSIM include? + + Monitoring and modeling + + PSIM includes (thanks to Michael Meissner) + a detailed model of most of the PowerPC + implementations to the functional unit level. + + + SMP + + The PowerPC ISA defines SMP synchronizing instructions. + This simulator implements a limited, but functional, + subset of the PowerPC synchronization instructions + behaviour. Programs that restrict their synchronization + primitives to those that work with this functional + sub-set (eg P() and V()) are able to run on the SMP + version of PSIM. + + People intending to use this system should study + the code implementing the lwarx instruction. + + ENDIAN SUPPORT + + PSIM implements the PowerPC's big and little (xor + endian) modes and correctly simulates code that + switches between these two modes. + + In addition, psim can model a true little-endian + machine. + + ISA (Instruction Set Architecture) models + + PSIM includes a model of the UEA, VEA and OEA. This + includes the time base registers (VEA) and HTAB + and BATS (OEA). + + In addition, a preliminary model of the 64 bit + PowerPC architecture is implemented. + + IO Hardware + + PSIM's internals are based around the concept + of a Device Tree. This tree intentionally + resembles that of the Device Tree found in + OpenBoot firmware. PSIM is flexible enough + to allow the user to fully configure this device + tree (and consequently the hardware model) at + run time. + + Run-time environments: + + PSIM's UEA model includes emulation for BSD + based UNIX system calls. + + PSIM's OEA model includes emulation of either: + + o OpenBoot client interface + + o MOTO's BUG interface. + + + Floating point + + Preliminary support for floating point is included. + + + Who would be interested in PSIM? + + o the curious + + Using psim, gdb, gcc and binutils the curious + user can construct an environment that allows + them to play with PowerPC Environment without + the need for real hardware. + + + o the analyst + + PSIM includes many (contributed) monitoring + features which (unlike many other simulators) + do not come with a great penalty in performance. + + Thus the performance analyst is able to use + this simulator to analyse the performance of + the system under test. + + If PSIM doesn't monitor a components of interest, + the source code is freely available, and hence + there is no hinderance to changing things + to meet a specific analysts needs. + + + o the serious SW developer + + PSIM models all three levels of the PowerPC + Architecture: UEA, VEA and OEA. Further, + the internal design is such that PSIM can + be extended to support additional requirements. + + + What performance analysis measurements can PSIM perform? + + Below is the output from a recent analysis run + (contributed by Michael Meissner): + + For the following program: + + long + simple_rand () + { + static unsigned long seed = 47114711; + unsigned long this = seed * 1103515245 + 12345; + seed = this; + /* cut-cut-cut - see the file RUN.psim */ + } + + Here is the current output generated with the -I switch on a P90 + (the compiler used is the development version of GCC with a new + scheduler replacing the old one): + + CPU #1 executed 41,994 AND instructions. + CPU #1 executed 519,785 AND Immediate instructions. + . + . + . + CPU #1 executed 1 System Call instruction. + CPU #1 executed 207,746 XOR instructions. + + CPU #1 executed 23,740,856 cycles. + CPU #1 executed 10,242,780 stalls waiting for data. + CPU #1 executed 1 stall waiting for a function unit. + . + . + . + CPU #1 executed 3,136,229 branch functional unit instructions. + CPU #1 executed 16,949,396 instructions that were accounted for in timing info. + CPU #1 executed 871,920 data reads. + CPU #1 executed 971,926 data writes. + CPU #1 executed 221 icache misses. + CPU #1 executed 16,949,396 instructions in total. + + Simulator speed was 250,731 instructions/second + + + What motivated PSIM? + + As an idea, psim was first discussed seriously during mid + 1994. At that time its main objectives were: + + + o good performance + + Many simulators loose out by only providing + a binary interface to the internals. This + interface eventually becomes a bottle neck + in the simulators performance. + + It was intended that PSIM would avoid this + problem by giving the user access to the + full source code. + + Further, by exploiting the power of modern + compilers it was hoped that PSIM would achieve + good performance with out having to compromise + its internal design. + + + o practical portability + + Rather than try to be portable to every + C compiler on every platform, it was decided + that PSIM would restrict its self to supporting + ANSI compilers that included the extension + of a long long type. + + GCC is one such compiler, consequently PSIM + should be portable to any machine running GCC. + + + o flexibility in its design + + PSIM should allow the user to select the + features required and customise the build + accordingly. By having the source code, + the compiler is able to eliminate any un + used features of the simulator. + + After all, let the compiler do the work. + + + o SMP + + A model that allowed the simulation of + SMP platforms with out the large overhead + often encountered with such models. + + + PSIM achieves each of these objectives. + + + Is PSIM PowerPC Platform (PPCP) (nee CHRP) Compliant? + + No. + + Among other things it does not have an Apple ROM socket. + + + Could PSIM be extended so that it models a CHRP machine? + + Yes. + + PSIM has been designed with the CHRP spec in mind. To model + a CHRP desktop the following would need to be added: + + o An apple ROM socket :-) + + o Model of each of the desktop IO devices + + o An OpenPIC device. + + o RTAS (Run Time Abstraction Services). + + o A fully populated device tree. + + + Is the source code available? + + Yes. + + The source code to PSIM is available under the terms of + the GNU Public Licence. This allows you to distribute + the source code for free but with certain conditions. + + See the file: + + ftp://archie.au/gnu/COPYING + + For details of the terms and conditions. + + + Where do I send bugs or report problems? + + There is a mailing list (subscribe through majordomo@ci.com.au) at: + + powerpc-psim@ci.com.au + + If I get the ftp archive updated I post a note to that mailing list. + In addition your welcome to send bugs or problems either to me or to + that e-mail list. + + This list currently averages zero articles a day. + + + Does PSIM have any limitations or problems? + + PSIM can't run rs6000/AIX binaries - At present PSIM can only + simulate static executables. Since an AIX executable is + never static, PSIM is unable to simulate its execution. + + PSIM is still under development - consequently there are going + to be bugs. + + See the file BUGS (included in the distribution) for any + other outstanding issues. + |