scummvm/backends/plugins/riscos/riscos-provider.cpp

130 lines
3.8 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#define FORBIDDEN_SYMBOL_ALLOW_ALL
#include "common/scummsys.h"
#if defined(DYNAMIC_MODULES) && defined(RISCOS)
#include "backends/plugins/riscos/riscos-provider.h"
#include "backends/plugins/elf/arm-loader.h"
#include "common/debug.h"
#include <kernel.h>
#include <swis.h>
// HACK: These two function are part of private API in libunixlib
// They let allocate and free data in the application space where the stack is placed below 64MB
// When using malloc with big chunks we end up in memory mapped areas above 64MB
extern "C" {
extern void *__stackalloc (size_t __size);
extern void __stackfree (void *__ptr);
}
// HACK: This is needed so that standard library functions that are only
// used in plugins can be found in the main executable.
void pluginHack() {
volatile float f = 0.0f;
volatile double d = 0.0;
volatile int i = 0;
byte *b = new (std::nothrow) byte[100];
f = tanhf(f);
f = logf(f);
f = log10f(f);
f = lroundf(f);
f = expf(f);
f = frexpf(f, NULL);
f = ldexpf(f, 1);
f = fmaxf(f, f);
f = fminf(f, f);
f = truncf(f);
d = nearbyint(d);
i = strcoll("dummyA", "dummyB");
rename("dummyA", "dummyB");
delete[] b;
}
class RiscOSDLObject : public ARMDLObject {
protected:
void flushDataCache(void *ptr, uint32 len) const override {
_kernel_swi_regs regs;
regs.r[0] = 1;
regs.r[1] = (int)ptr;
regs.r[2] = (int)ptr + len;
_kernel_swi(OS_SynchroniseCodeAreas, &regs, &regs);
}
};
/**
* On 26-bit RISC OS, plugins need to be allocated in the first 64 MB
* of RAM so that it can be executed. This may not be the case when using
* the default allocators, which use dynamic areas for large allocations.
*/
class RiscOSDLObject_AS : public RiscOSDLObject {
protected:
void *allocateMemory(uint32 align, uint32 size) override {
// Allocate with worst case alignment in application space
void *p = __stackalloc(size + sizeof(uintptr) + align - 1);
void *np = (void *)(((uintptr)p + align - 1) & (-align));
*(uintptr *)((byte *)np + size) = (uintptr)p;
debug(8, "Allocated %p while alignment was %d: using %p", p, align, np);
return np;
}
void deallocateMemory(void *ptr, uint32 size) override {
void *p = (void *)*(uintptr *)((byte *)ptr + size);
debug(8, "Freeing %p which was allocated at %p", ptr, p);
__stackfree(p);
}
};
RiscOSPluginProvider::RiscOSPluginProvider() : _is32bit(false) {
__asm__ volatile (
"SUBS %[is32bit], r0, r0\n\t" /* Set at least one status flag and set is32bits to 0 */
"TEQ pc, pc\n\t" /* First operand never contains flags while second one contains them in 26-bits only */
"MOVEQ %[is32bit], #1\n\t" /* Set to 1 only if EQ flag is set */
: [is32bit] "=r" (_is32bit)
: /* no inputs */
: "cc");
}
Plugin *RiscOSPluginProvider::createPlugin(const Common::FSNode &node) const {
if (_is32bit) {
return new TemplatedELFPlugin<RiscOSDLObject>(node.getPath());
} else {
return new TemplatedELFPlugin<RiscOSDLObject_AS>(node.getPath());
}
}
#endif // defined(DYNAMIC_MODULES) && defined(RISCOS)