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Revision 1.25 - (view) (annotate) - [select for diffs]
Tue Dec 27 07:22:18 2011 UTC (2 years, 3 months ago) by asvitkine
Branch: MAIN
CVS Tags: HEAD
Changes since 1.24: +1 -1 lines
Diff to previous 1.24
fix a warning


Revision 1.24 - (view) (annotate) - [select for diffs]
Tue Aug 18 18:26:10 2009 UTC (4 years, 8 months ago) by asvitkine
Branch: MAIN
Changes since 1.23: +1 -1 lines
Diff to previous 1.23
[Michael Schmitt]
Attached is a patch to SheepShaver to fix memory allocation problems when OS X 10.5 is the host. It also relaxes the 512 MB RAM limit on OS X hosts.


Problem
-------
Some users have been unable to run SheepShaver on OS X 10.5 (Leopard) hosts. The symptom is error "ERROR: Cannot map RAM: File already exists".

SheepShaver allocates RAM at fixed addresses. If it is running in "Real" addressing mode, and can't allocate at address 0, then it was hard-coded to allocate the RAM area at 0x20000000. The ROM area as allocated at 0x40800000.

The normal configuration is for SheepShaver to run under SDL, which is a Cocoa wrapper. By the time SheepShaver does its memory allocations, the Cocoa application has already started. The result is the SheepShaver memory address space already contains libraries, fonts, Input Managers, and IOKit areas.

On Leopard hosts these areas can land on the same addresses SheepShaver needs, so SheepShaver's memory allocation fails.


Solution
--------
The approach is to change SheepShaver (on Unix & OS X hosts) to allocate the RAM area anywhere it can find the space, rather than at a fixed address.

This could result in the RAM allocated higher than the ROM area, which causes a crash. To prevent this from occurring, the RAM and ROM areas are allocated contiguously.

Previously the ROM starting address was a constant ROM_BASE, which was used throughout the source files. The ROM start address is now a variable ROMBase. ROMBase is allocated and set by main_*.cpp just like RAMBase.

A side-effect of this change is that it lifts the 512 MB RAM limit for OS X hosts. The limit was because the fixed RAM and ROM addresses were such that the RAM could only be 512 MB before it overlapped the ROM area.


Impact
------
The change to make ROMBase a variable is throughout all hosts & addressing modes.

The RAM and ROM areas will only shift when run on Unix & OS X hosts, otherwise the same fixed allocation address is used as before.

This change is limited to "Real" addressing mode. Unlike Basilisk II, SheepShaver *pre-calculates* the offset for "Direct" addressing mode; the offset is compiled into the program. If the RAM address were allowed to shift, it could result in the RAM area wrapping around address 0.


Changes to main_unix.cpp
------------------------
1. Real addressing mode no longer defines a RAM_BASE constant.

2. The base address of the Mac ROM (ROMBase) is defined and exported by this program.

3. Memory management helper vm_mac_acquire is renamed to vm_mac_acquire_fixed. Added a new memory management helper vm_mac_acquire, which allocates memory at any address.

4. Changed and rearranged the allocation of RAM and ROM areas.

Before it worked like this:

  - Allocate ROM area
  - If can, attempt to allocate RAM at address zero
  - If RAM not allocated at 0, allocate at fixed address

We still want to try allocating the RAM at zero, and if using DIRECT addressing we're still going to use the fixed addresses. So we don't know where the ROM should be until after we do the RAM. The new logic is:

  - If can, attempt to allocate RAM at address zero
  - If RAM not allocated at 0
      if REAL addressing
         allocate RAM and ROM together. The ROM address is aligned to a 1 MB boundary
      else (direct addressing)
         allocate RAM at fixed address
  - If ROM hasn't been allocated yet, allocate at fixed address

5. Calculate ROMBase and ROMBaseHost based on where the ROM was loaded.

6. There is a crash if the RAM is allocated too high. To try and catch this, check if it was allocated higher than the kernel data address.

7. Change subsequent code from using constant ROM_BASE to variable ROMBase.


Changes to Other Programs
-------------------------
emul_op.cpp, main.cpp, name_registery.cpp, rom_patches.cpp, rsrc_patches.cpp, emul_ppc.cpp, sheepshaver_glue.cpp, ppc-translate-cpp:
Change from constant ROM_BASE to variable ROMBase.

ppc_asm.S: It was setting register to a hard-coded literal address: 0x40b0d000. Changed to set it to ROMBase + 0x30d000.

ppc_asm.tmpl: It defined a macro ASM_LO16 but it assumed that the macro would always be used with operands that included a register specification. This is not true. Moved the register specification from the macro to the macro invocations.

main_beos.cpp, main_windows.cpp: Since the subprograms are all expecting a variable ROMBase, all the main_*.cpp pgrams have to define and export it. The ROM_BASE constant is moved here for consistency. The mains for beos and windows just allocate the ROM at the same fixed address as before, set ROMBaseHost and ROMBase to that address, and then use ROMBase for the subsequent code.

cpu_emulation.h: removed ROM_BASE constant. This value is moved to the main_*.cpp modules, to be consistent with RAM_BASE.

user_strings_unix.cpp, user_strings_unix.h: Added new error messages related to errors that occur when the RAM and ROM are allocated anywhere.


Revision 1.23 - (view) (annotate) - [select for diffs]
Tue Jan 1 09:47:38 2008 UTC (6 years, 3 months ago) by gbeauche
Branch: MAIN
Changes since 1.22: +1 -1 lines
Diff to previous 1.22
Happy New Year!


Revision 1.22 - (view) (annotate) - [select for diffs]
Sat Jul 2 17:51:43 2005 UTC (8 years, 9 months ago) by gbeauche
Branch: MAIN
Changes since 1.21: +10 -0 lines
Diff to previous 1.21
Issue a SysError(dsOldSystem) if we are trying to use MacOS < 8.1.0 with a
NewWorld ROM. That may be 8.1.0 included but original iMac had a NewWorld
ROM compatible system.

Otherwise we will crash because the boot routine is trying to execute code
through unitialized descriptor that points to 0x13ff, which is obviously
wrong (and unaligned on word-boundaries for 68k code).


Revision 1.21 - (view) (annotate) - [select for diffs]
Thu Jun 30 10:17:58 2005 UTC (8 years, 9 months ago) by gbeauche
Branch: MAIN
Changes since 1.20: +2 -2 lines
Diff to previous 1.20
Improve idle wait mechanism. Now, the emulator thread can be suspended
(idle_wait) until events arrived and notified through TriggerInterrupt().
i.e. we no longer sleep a fixed amount of time on platforms that support
a thread wait/signal mechanism.


Revision 1.20 - (view) (annotate) - [select for diffs]
Sun Mar 27 22:06:52 2005 UTC (9 years ago) by gbeauche
Branch: MAIN
Changes since 1.19: +2 -2 lines
Diff to previous 1.19
disable 68k DR emulator for now (not stable enough yet)


Revision 1.19 - (view) (annotate) - [select for diffs]
Sat Mar 5 19:07:35 2005 UTC (9 years, 1 month ago) by gbeauche
Branch: MAIN
Changes since 1.18: +0 -7 lines
Diff to previous 1.18
Enable high precision timings on POSIX systems supporting clock_nanosleep().
Since pthread_suspend_np() is not available to Linux (but NetBSD 2.0), thread
suspend is implemented likewise to boehm-gc.


Revision 1.18 - (view) (annotate) - [select for diffs]
Sun Jan 30 21:48:19 2005 UTC (9 years, 2 months ago) by gbeauche
Branch: MAIN
Changes since 1.17: +1 -1 lines
Diff to previous 1.17
Happy New Year 2005!


Revision 1.17 - (view) (annotate) - [select for diffs]
Sun Dec 19 09:01:04 2004 UTC (9 years, 4 months ago) by gbeauche
Branch: MAIN
Changes since 1.16: +1 -1 lines
Diff to previous 1.16
FindLibSymbol() returns an address in MacOS address space. Likewise for
Mac_sysalloc(). i.e. make it return an uint32.


Revision 1.16 - (view) (annotate) - [select for diffs]
Mon Nov 22 22:04:38 2004 UTC (9 years, 4 months ago) by gbeauche
Branch: MAIN
Changes since 1.15: +6 -5 lines
Diff to previous 1.15
Use BUILD_SHEEPSHAVER_PROCEDURE to allocate static procedures into the
SheepShaver globals. Fix build of sheepshaver_glue.cpp without JIT.


Revision 1.15 - (view) (annotate) - [select for diffs]
Sat Nov 13 14:09:15 2004 UTC (9 years, 5 months ago) by gbeauche
Branch: MAIN
Changes since 1.14: +7 -7 lines
Diff to previous 1.14
Implement Direct Addressing mode similarly to Basilisk II. This is to get
SheepShaver working on OSes that don't support maipping of Low Memory globals
at 0x00000000, e.g. Windows.


Revision 1.14 - (view) (annotate) - [select for diffs]
Sun Jun 20 19:10:02 2004 UTC (9 years, 10 months ago) by gbeauche
Branch: MAIN
Changes since 1.13: +8 -0 lines
Diff to previous 1.13
MacOS 9.0.4 support. ;-)


Revision 1.13 - (view) (annotate) - [select for diffs]
Thu Jun 3 21:52:54 2004 UTC (9 years, 10 months ago) by gbeauche
Branch: MAIN
Changes since 1.12: +11 -10 lines
Diff to previous 1.12
Add "jit68k" prefs item to enable built-in 68k DR emulator.


Revision 1.12 - (view) (annotate) - [select for diffs]
Mon May 31 11:00:13 2004 UTC (9 years, 10 months ago) by gbeauche
Branch: MAIN
Changes since 1.11: +10 -11 lines
Diff to previous 1.11
Disable DR Cache for now, as I don't know why it occasionnally crashes.


Revision 1.11 - (view) (annotate) - [select for diffs]
Mon May 31 10:02:20 2004 UTC (9 years, 10 months ago) by gbeauche
Branch: MAIN
Changes since 1.10: +2 -2 lines
Diff to previous 1.10
Enable DR emulator with OldWorld ROMs too. It turned out that translated
code was also trying to access Serial memory.

Note however that I noticed some rare crashes with the DR emulator.
Probably caused by nested runs from EmulOps? We'd really want a native
68k emulator too for Execute68k() things.


Revision 1.10 - (view) (annotate) - [select for diffs]
Mon May 31 09:04:42 2004 UTC (9 years, 10 months ago) by gbeauche
Branch: MAIN
Changes since 1.9: +12 -9 lines
Diff to previous 1.9
Enable Apple DR emulator from NewWorld ROMs only.


Revision 1.9 - (view) (annotate) - [select for diffs]
Sat May 15 16:36:41 2004 UTC (9 years, 11 months ago) by gbeauche
Branch: MAIN
Changes since 1.8: +9 -5 lines
Diff to previous 1.8
"idlewait" support for Linux and NewWorld ROMs


Revision 1.8 - (view) (annotate) - [select for diffs]
Mon Jan 12 15:37:18 2004 UTC (10 years, 3 months ago) by cebix
Branch: MAIN
Changes since 1.7: +1 -1 lines
Diff to previous 1.7
Happy New Year! :)


Revision 1.7 - (view) (annotate) - [select for diffs]
Sat Jan 10 08:46:56 2004 UTC (10 years, 3 months ago) by gbeauche
Branch: MAIN
Changes since 1.6: +4 -4 lines
Diff to previous 1.6
Make sure 68k procedures are stored on 16-bit word boundaries.


Revision 1.6 - (view) (annotate) - [select for diffs]
Thu Dec 4 23:37:35 2003 UTC (10 years, 4 months ago) by gbeauche
Branch: MAIN
Changes since 1.5: +0 -8 lines
Diff to previous 1.5
Use a unique ExecuteNative() interface in any case, i.e. native & emulated


Revision 1.5 - (view) (annotate) - [select for diffs]
Thu Dec 4 17:26:35 2003 UTC (10 years, 4 months ago) by gbeauche
Branch: MAIN
Changes since 1.4: +3 -8 lines
Diff to previous 1.4
Add new thunking system for 64-bit fixes.


Revision 1.4 - (view) (annotate) - [select for diffs]
Sun Oct 26 08:48:48 2003 UTC (10 years, 5 months ago) by gbeauche
Branch: MAIN
Changes since 1.3: +1 -1 lines
Diff to previous 1.3
fix MakeExecutable patch for little endian systems


Revision 1.3 - (view) (annotate) - [select for diffs]
Sun Oct 12 05:44:11 2003 UTC (10 years, 6 months ago) by gbeauche
Branch: MAIN
Changes since 1.2: +3 -1 lines
Diff to previous 1.2
- Handle MakeExecutable() replacement
- Disable predecode cache in CVS for now
- Fix flight recorder ordering in predecode cache mode


Revision 1.2 - (view) (annotate) - [select for diffs]
Sun Sep 7 14:33:51 2003 UTC (10 years, 7 months ago) by gbeauche
Branch: MAIN
Changes since 1.1: +12 -5 lines
Diff to previous 1.1
- Integrate new NativeOp instructions to be used as trampolines to call
  native functions from ppc code.
- Little endian fixes in emul_op.cpp
- Add new 'gpch' 750 patch to workaround crash with MacOS 8.6
- Don't crash in Process Manager on reset/shutdown with MacOS 8.6
- We also have an experimental interrupt thread in emulation mode


Revision 1.1.1.1 - (view) (annotate) - [select for diffs] (vendor branch)
Mon Feb 4 16:58:13 2002 UTC (12 years, 2 months ago) by cebix
Branch: cebix
CVS Tags: start
Changes since 1.1: +0 -0 lines
Diff to previous 1.1 , to next main 1.25
Imported sources


Revision 1.1 - (view) (annotate) - [select for diffs]
Mon Feb 4 16:58:13 2002 UTC (12 years, 2 months ago) by cebix
Branch: MAIN
Branch point for: cebix
Initial revision


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