/src/rt/arch/i386/context.cpp
http://github.com/jruderman/rust · C++ · 73 lines · 48 code · 17 blank · 8 comment · 1 complexity · af0b2bcaa4d23a78716b22e0e9b824d9 MD5 · raw file
- #include "context.h"
- #include "../../rust_globals.h"
- extern "C" uint32_t CDECL swap_registers(registers_t *oregs,
- registers_t *regs)
- asm ("swap_registers");
- context::context()
- {
- assert((void*)®s == (void*)this);
- }
- void context::swap(context &out)
- {
- swap_registers(&out.regs, ®s);
- }
- void context::call(void *f, void *arg, void *stack) {
- // Get the current context, which we will then modify to call the
- // given function.
- swap(*this);
- // set up the trampoline frame
- uint32_t *sp = (uint32_t *)stack;
- // Shift the stack pointer so the alignment works out right.
- sp = align_down(sp) - 3;
- *--sp = (uint32_t)arg;
- // The final return address. 0 indicates the bottom of the stack
- *--sp = 0;
- regs.esp = (uint32_t)sp;
- regs.eip = (uint32_t)f;
- // Last base pointer on the stack should be 0
- regs.ebp = 0;
- }
- #if 0
- // This is some useful code to check how the registers struct got
- // layed out in memory.
- int main() {
- registers_t regs;
- printf("Register offsets\n");
- #define REG(r) \
- printf(" %6s: +%ld\n", #r, (intptr_t)®s.r - (intptr_t)®s);
- REG(eax);
- REG(ebx);
- REG(ecx);
- REG(edx);
- REG(ebp);
- REG(esi);
- REG(edi);
- REG(esp);
- REG(cs);
- REG(ds);
- REG(ss);
- REG(es);
- REG(fs);
- REG(gs);
- REG(eflags);
- REG(eip);
- return 0;
- }
- #endif