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| -rw-r--r-- | sim/ppc/README.psim | 473 |
1 files changed, 325 insertions, 148 deletions
diff --git a/sim/ppc/README.psim b/sim/ppc/README.psim index cb34a37..518b412 100644 --- a/sim/ppc/README.psim +++ b/sim/ppc/README.psim @@ -18,17 +18,16 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. -This directory contains the source code to the program PSIM that -implements a model of a PowerPC platform. PSIM can either be built -standalone or as part of the debugger GDB. +This directory contains the source code to the program PSIM. What is PSIM? - PSIM is an ANSI C program that can be configured to model - various PowerPC platforms. + PSIM is an ANSI C program that implements an instruction + level model of the PowerPC architecture. - The platform that is modeled can vary from: + It can be configured to model various PowerPC platforms + and include: o A user program environment (UEA) complete with emulated system calls @@ -39,70 +38,9 @@ What is PSIM? interacting with each other and various modeled hardware devices. + For each of these models PSIM is able perform a detailed + analysis of the machines performance. -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. - - -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 - inteface eventually becomming 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 compromize - 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 suporting - ANSI compilers that included the extension - of a long long type. - - GCC is one such compiler, consequenly PSIM - should be portable to any machine running GCC. - - - o flexability in its design - - PSIM should allow the user to select the - features required and customize the build - accordingly. By having the source code, - the compler 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. Who would be interested in PSIM? @@ -201,37 +139,304 @@ What features does PSIM have? of new hardware devices so that they can be included in a custom hardware model. - Emulation + OS-Emulation + + PSIM's UEA model includes emulation for UNIX system + calls. + + PSIM's OEA model includes emulation of either: + + o OpenBoot client interface + + o MOTO's BUG interface. - PSIM is able (UEA) to emulate UNIX calls - based on NetBSD abi through to (preliminary) - the ROM rom calls found in common firmware - (OpenBoot and BUGAPI). Floating point Preliminary suport for floating point is included. - Real kernels don't need floating point. -Is PSIM CHRP Compliant? + +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; + return this >> 8; + } + + unsigned long int + random_bitstring () + { + unsigned long int x; + int ran, n_bits; + int tot_bits = 0; + + x = 0; + for (;;) + { + ran = simple_rand (); + n_bits = (ran >> 1) % 16; + tot_bits += n_bits; + + if (n_bits == 0) + return x; + else + { + x <<= n_bits; + if (ran & 1) + x |= (1 << n_bits) - 1; + + if (tot_bits > 8 * sizeof (long) + 6) + return x; + } + } + } + + #define ABS(x) ((x) >= 0 ? (x) : -(x)) + + main () + { + int i; + + for (i = 0; i < 50000; i++) + { + unsigned long x, y; + x = random_bitstring (); + y = random_bitstring (); + + if (sizeof (int) == sizeof (long)) + goto save_time; + + { unsigned long xx = x, yy = y, r1, r2; + if (yy == 0) continue; + r1 = xx / yy; + r2 = xx % yy; + if (r2 >= yy || r1 * yy + r2 != xx) + abort (); + } + { signed long xx = x, yy = y, r1, r2; + if ((unsigned long) xx << 1 == 0 && yy == -1) + continue; + r1 = xx / yy; + r2 = xx % yy; + if (ABS (r2) >= (unsigned long) ABS (yy) || (signed long) (r1 * yy + r2) != xx) + abort (); + } + save_time: + { unsigned int xx = x, yy = y, r1, r2; + if (yy == 0) continue; + r1 = xx / yy; + r2 = xx % yy; + if (r2 >= yy || r1 * yy + r2 != xx) + abort (); + } + { signed int xx = x, yy = y, r1, r2; + if ((unsigned int) xx << 1 == 0 && yy == -1) + continue; + r1 = xx / yy; + r2 = xx % yy; + if (ABS (r2) >= (unsigned int) ABS (yy) || (signed int) (r1 * yy + r2) != xx) + abort (); + } + { unsigned short xx = x, yy = y, r1, r2; + if (yy == 0) continue; + r1 = xx / yy; + r2 = xx % yy; + if (r2 >= yy || r1 * yy + r2 != xx) + abort (); + } + { signed short xx = x, yy = y, r1, r2; + r1 = xx / yy; + r2 = xx % yy; + if (ABS (r2) >= (unsigned short) ABS (yy) || (signed short) (r1 * yy + r2) != xx) + abort (); + } + { unsigned char xx = x, yy = y, r1, r2; + if (yy == 0) continue; + r1 = xx / yy; + r2 = xx % yy; + if (r2 >= yy || r1 * yy + r2 != xx) + abort (); + } + { signed char xx = x, yy = y, r1, r2; + r1 = xx / yy; + r2 = xx % yy; + if (ABS (r2) >= (unsigned char) ABS (yy) || (signed char) (r1 * yy + r2) != xx) + abort (); + } + } + + exit (0); + } + + Here is the current output generated with the -I switch on a 90 Mhz + pentium (the compiler used is the devlopment 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 680,058 Add instructions. + CPU #1 executed 41,994 Add Extended instructions. + CPU #1 executed 921,916 Add Immediate instructions. + CPU #1 executed 221,199 Add Immediate Carrying instructions. + CPU #1 executed 943,823 Add Immediate Shifted instructions. + CPU #1 executed 471,909 Add to Zero Extended instructions. + CPU #1 executed 571,915 Branch instructions. + CPU #1 executed 1,992,403 Branch Conditional instructions. + CPU #1 executed 571,910 Branch Conditional to Link Register instructions. + CPU #1 executed 320,431 Compare instructions. + CPU #1 executed 471,911 Compare Immediate instructions. + CPU #1 executed 145,867 Compare Logical instructions. + CPU #1 executed 442,414 Compare Logical Immediate instructions. + CPU #1 executed 1 Condition Register XOR instruction. + CPU #1 executed 103,873 Divide Word instructions. + CPU #1 executed 104,275 Divide Word Unsigned instructions. + CPU #1 executed 132,510 Extend Sign Byte instructions. + CPU #1 executed 178,895 Extend Sign Half Word instructions. + CPU #1 executed 871,920 Load Word and Zero instructions. + CPU #1 executed 41,994 Move From Condition Register instructions. + CPU #1 executed 100,005 Move from Special Purpose Register instructions. + CPU #1 executed 100,002 Move to Special Purpose Register instructions. + CPU #1 executed 804,619 Multiply Low Word instructions. + CPU #1 executed 421,201 OR instructions. + CPU #1 executed 471,910 OR Immediate instructions. + CPU #1 executed 1,292,020 Rotate Left Word Immediate then AND with Mask instructions. + CPU #1 executed 663,613 Shift Left Word instructions. + CPU #1 executed 1,151,564 Shift Right Algebraic Word Immediate instructions. + CPU #1 executed 871,922 Store Word instructions. + CPU #1 executed 100,004 Store Word with Update instructions. + CPU #1 executed 887,804 Subtract From instructions. + CPU #1 executed 83,988 Subtract From Immediate Carrying 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 1 stall waiting for serialization. + CPU #1 executed 1,757,900 times a writeback slot was unavilable. + CPU #1 executed 1,088,135 branches. + CPU #1 executed 2,048,093 conditional branches fell through. + CPU #1 executed 1,088,135 successful branch predictions. + CPU #1 executed 904,268 unsuccessful branch predictions. + CPU #1 executed 742,557 branch if the condition is FALSE conditional branches. + CPU #1 executed 1,249,846 branch if the condition is TRUE conditional branches. + CPU #1 executed 571,910 branch always conditional branches. + CPU #1 executed 9,493,653 1st single cycle integer functional unit instructions. + CPU #1 executed 1,220,900 2nd single cycle integer functional unit instructions. + CPU #1 executed 1,254,768 multiple cycle integer functional unit instructions. + CPU #1 executed 1,843,846 load/store functional unit instructions. + 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 compromize + 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 suporting + ANSI compilers that included the extension + of a long long type. + + GCC is one such compiler, consequenly PSIM + should be portable to any machine running GCC. + + + o flexability in its design + + PSIM should allow the user to select the + features required and customize the build + accordingly. By having the source code, + the compler 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. - However, PSIM does include all the hooks that are needed to - construct a model of a CHRP compliant platform. + Among other things it does not have an Apple ROM socket. + + +Can PSIM be configured so that it models a CHRP machine? + + Yes. + + PSIM has been designed with the CHRP spec in mind. To model + a CHRP desktop a user would need to add the following: + + o An apple rom socket :-) + + o Model of each of the desktop IO devices + (some may already be implemented). + + o An OpenPIC (Open Programmable Interrupt + Controller) device. (it may by now be + implemented). - That is: + o RTAS (Run Time Abstraction Services). - o OpenBoot client software + o A fully populated device tree. - o OpenPIC interrupt controller - o Hooks to implement a RTAS interface +Is the source code available? + + Yes. - o the ability to add a model of each of the - hardware devices required by a CHRP compliant - desktop. + 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. How do I build PSIM? @@ -240,7 +445,7 @@ How do I build PSIM? gdb-4.15.tar.gz From your favorite GNU ftp site. - I've also tested psim-951016 with + I've also tested psim with gdb-4.15.1. If you would prefer a graphical development environment then PSIM can also be built with @@ -252,20 +457,26 @@ How do I build PSIM? This file. - ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+psim-951016.diff.gz + ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+psim.diff.gz + + Firstly this file contains a few + minor changes to gdb-4.15 so that it + will build PSIM as part of GDB. - This contains a few minor patches to - gdb-4.15 so that will include psim - when it is built. + ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+note.diff.gz - ftp://ftp.ci.com.au/pub/clayton/psim-test-951016.tar.gz + Add suport for note sections (used + by OpenBoot PowerPC programs). - (Optional) A scattering of pre-compiled - programs that run under the simulator. + + ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+attach.diff.gz + + Allow the gdb attach command to + work with simulators. - ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+psim-951016.tar.gz + ftp://ftp.ci.com.au/pub/clayton/psim-960119.tar.gz This contains the psim files proper. @@ -280,36 +491,17 @@ How do I build PSIM? installing gnu's patch. - In addition, I'm slowly building up a set of useful patches - to gdb-4.15 that are useful. You will want to also apply - these patches: - - - ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+attach.diff.gz - - Patch to gdb that allows the `attach' - command to be used when connecting to a - simulator. - - See that file for more information. - - ftp://ftp.ci.com.au/pub/clayton/gdb-4.15+note.diff.gz - - Patch to gdb's bfd that adds basic support - for a .note section. OpenBoot makes - use of a .note section when loading a - boot image. - - Procedure: 0. A starting point $ ls -1 - gdb-4.15+psim-951016.diff.gz - gdb-4.15+psim-951016.tar.gz + gdb-4.15+attach.diff.gz + gdb-4.15+note.diff.gz + gdb-4.15+psim.diff.gz + gdb-4.15+psim.diff.gz gdb-4.15.tar.gz - psim-test-951016.tar.gz + psim-960119.tar.gz 1. Unpack gdb @@ -322,11 +514,11 @@ How do I build PSIM? $ cd gdb-4.15 - $ gunzip < ../gdb-4.15+psim-951016.diff.gz | more - $ gunzip < ../gdb-4.15+psim-951016.diff.gz | patch -p1 + $ gunzip < ../gdb-4.15+psim.diff.gz | more + $ gunzip < ../gdb-4.15+psim.diff.gz | patch -p1 - $ gunzip < ../gdb-4.15+psim-951016.tar.gz | tar tvf - - $ gunzip < ../gdb-4.15+psim-951016.tar.gz | tar xvf - + $ gunzip < ../gdb-4.15+psim-960119.tar.gz | tar tvf - + $ gunzip < ../gdb-4.15+psim-960119.tar.gz | tar xvf - You may also want to consider applying the `attach' and `note' patches that are available vis: @@ -349,6 +541,12 @@ How do I build PSIM? eabisim is needed as by default (because PSIM needs GCC) the simulator is not built. + [If building with a more recent gdb snapshot then the + command: + + $CC=gcc ./configure --enable-sim-powerpc + + is used.] 4. Build @@ -378,23 +576,7 @@ Is there a more recent version of PSIM and if so, how would I build it? (that include new features) are made available. Several of the more recent snapshots are: - ftp://ftp.ci.com.au/pub/clayton/psim-951219.tar.gz - - Hopefully merges in Michael stuff - with mine, adds multiple emulations - (OpenBoot and NetBSD), revamps - inline stuff, rearanges devices so - that phandls and ihandles can be - implemented. - - ftp://ftp.ci.com.au/pub/clayton/psim-951203.tar.gz - - A good snapshot - - This includes extensions from Michael - Meissner that add monitoring of the - PowerPC's register and bus architectures. - + <to-be-advised> To build/install one of these snapshots, you replace the current gdb/sim/ppc directory with the one in the update, @@ -430,7 +612,7 @@ Are there any example programs that can be run on PSIM? that fixes do not introduce new bugs. This test suite like psim is updated: - ftp://ftp.ci.com.au/pub/clayton/psim-test-951218.tar.gz + ftp://ftp.ci.com.au/pub/clayton/psim-test-960118.tar.gz Prebuilt test programs for PSIM. Includes examples of UEA, VEA and @@ -438,11 +620,6 @@ Are there any example programs that can be run on PSIM? Requires gcc-2.7.2 and binutils-2.6 to rebuild. - ftp://ftp.ci.com.au/pub/clayton/psim-test-951016.tar.gz - - (Optional) A scattering of pre-compiled - programs that run under the simulator. - How do I use the simulator? @@ -515,9 +692,9 @@ Does PSIM have any limitations or problems? Who helped? - Thanks go to the following who each helped in some way. + Thanks go to the following who each helped in their own + way: Allen Briggs, Bett Koch, David Edelsohn, Gordon Irlam, - Michael Meissner, Bob Mercier, Richard Perini, + Michael Meissner, Bob Mercier, Richard Perini, Dale Rahn Richard Stallman, Mitchele Walker - |