80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
/*
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* this is the internal transfer function.
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*
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* HISTORY
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* 14-Aug-06 File creation. Ported from Arm Thumb. Sylvain Baro
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* 3-Sep-06 Commented out saving of r1-r3 (r4 already commented out) as I
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* read that these do not need to be saved. Also added notes and
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* errors related to the frame pointer. Richard Tew.
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*
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* NOTES
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*
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* It is not possible to detect if fp is used or not, so the supplied
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* switch function needs to support it, so that you can remove it if
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* it does not apply to you.
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*
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* POSSIBLE ERRORS
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*
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* "fp cannot be used in asm here"
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*
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* - Try commenting out "fp" in REGS_TO_SAVE.
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*
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*/
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#define STACK_REFPLUS 1
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#ifdef SLP_EVAL
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#define STACK_MAGIC 0
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#define REG_SP "sp"
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#define REG_SPSP "sp,sp"
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#ifdef __thumb__
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#define REG_FP "r7"
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#define REG_FPFP "r7,r7"
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#define REGS_TO_SAVE_GENERAL "r4", "r5", "r6", "r8", "r9", "r10", "r11", "lr"
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#else
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#define REG_FP "fp"
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#define REG_FPFP "fp,fp"
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#define REGS_TO_SAVE_GENERAL "r4", "r5", "r6", "r7", "r8", "r9", "r10", "lr"
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#endif
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#if defined(__SOFTFP__)
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#define REGS_TO_SAVE REGS_TO_SAVE_GENERAL
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#elif defined(__VFP_FP__)
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#define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "d8", "d9", "d10", "d11", \
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"d12", "d13", "d14", "d15"
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#elif defined(__MAVERICK__)
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#define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "mvf4", "mvf5", "mvf6", "mvf7", \
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"mvf8", "mvf9", "mvf10", "mvf11", \
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"mvf12", "mvf13", "mvf14", "mvf15"
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#else
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#define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "f4", "f5", "f6", "f7"
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#endif
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static int
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#ifdef __GNUC__
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__attribute__((optimize("no-omit-frame-pointer")))
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#endif
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slp_switch(void)
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{
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void *fp;
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register int *stackref, stsizediff;
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int result;
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__asm__ volatile ("" : : : REGS_TO_SAVE);
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__asm__ volatile ("mov r0," REG_FP "\n\tstr r0,%0" : "=m" (fp) : : "r0");
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__asm__ ("mov %0," REG_SP : "=r" (stackref));
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{
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SLP_SAVE_STATE(stackref, stsizediff);
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__asm__ volatile (
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"add " REG_SPSP ",%0\n"
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"add " REG_FPFP ",%0\n"
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:
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: "r" (stsizediff)
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);
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SLP_RESTORE_STATE();
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}
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__asm__ volatile ("ldr r0,%1\n\tmov " REG_FP ",r0\n\tmov %0, #0" : "=r" (result) : "m" (fp) : "r0");
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__asm__ volatile ("" : : : REGS_TO_SAVE);
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return result;
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}
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#endif
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