JezK
Edit File: switch_arm32_gcc.h
/* * this is the internal transfer function. * * HISTORY * 14-Aug-06 File creation. Ported from Arm Thumb. Sylvain Baro * 3-Sep-06 Commented out saving of r1-r3 (r4 already commented out) as I * read that these do not need to be saved. Also added notes and * errors related to the frame pointer. Richard Tew. * * NOTES * * It is not possible to detect if fp is used or not, so the supplied * switch function needs to support it, so that you can remove it if * it does not apply to you. * * POSSIBLE ERRORS * * "fp cannot be used in asm here" * * - Try commenting out "fp" in REGS_TO_SAVE. * */ #define STACK_REFPLUS 1 #ifdef SLP_EVAL #define STACK_MAGIC 0 #define REG_SP "sp" #define REG_SPSP "sp,sp" #ifdef __thumb__ #define REG_FP "r7" #define REG_FPFP "r7,r7" #define REGS_TO_SAVE_GENERAL "r4", "r5", "r6", "r8", "r9", "r10", "r11", "lr" #else #define REG_FP "fp" #define REG_FPFP "fp,fp" #define REGS_TO_SAVE_GENERAL "r4", "r5", "r6", "r7", "r8", "r9", "r10", "lr" #endif #if defined(__SOFTFP__) #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL #elif defined(__VFP_FP__) #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "d8", "d9", "d10", "d11", \ "d12", "d13", "d14", "d15" #elif defined(__MAVERICK__) #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "mvf4", "mvf5", "mvf6", "mvf7", \ "mvf8", "mvf9", "mvf10", "mvf11", \ "mvf12", "mvf13", "mvf14", "mvf15" #else #define REGS_TO_SAVE REGS_TO_SAVE_GENERAL, "f4", "f5", "f6", "f7" #endif static int #ifdef __GNUC__ __attribute__((optimize("no-omit-frame-pointer"))) #endif slp_switch(void) { void *fp; register int *stackref, stsizediff; int result; __asm__ volatile ("" : : : REGS_TO_SAVE); __asm__ volatile ("mov r0," REG_FP "\n\tstr r0,%0" : "=m" (fp) : : "r0"); __asm__ ("mov %0," REG_SP : "=r" (stackref)); { SLP_SAVE_STATE(stackref, stsizediff); __asm__ volatile ( "add " REG_SPSP ",%0\n" "add " REG_FPFP ",%0\n" : : "r" (stsizediff) ); SLP_RESTORE_STATE(); } __asm__ volatile ("ldr r0,%1\n\tmov " REG_FP ",r0\n\tmov %0, #0" : "=r" (result) : "m" (fp) : "r0"); __asm__ volatile ("" : : : REGS_TO_SAVE); return result; } #endif