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/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.org/license.html
*/
/**
* Thread Switching Functions for the Cortex M4 & M7 with hardware floating point
*
* Use the EABI calling standard (ARM's AAPCS) - Save r4 - r11 and floating point
* The context is saved at the current stack location and a pointer is maintained in the thread structure.
*/
#if GFX_COMPILER == GFX_COMPILER_GCC || GFX_COMPILER == GFX_COMPILER_CYGWIN || GFX_COMPILER == GFX_COMPILER_MINGW32 || GFX_COMPILER == GFX_COMPILER_MINGW64
#define GFX_THREADS_DONE
#define _gfxThreadsInit()
static __attribute__((pcs("aapcs-vfp"),naked)) void _gfxTaskSwitch(thread *oldt, thread *newt) {
__asm__ volatile ( "push {r4, r5, r6, r7, r8, r9, r10, r11, lr} \n\t"
"vpush {s16-s31} \n\t"
"str sp, %[oldtcxt] \n\t"
"ldr sp, %[newtcxt] \n\t"
"vpop {s16-s31} \n\t"
"pop {r4, r5, r6, r7, r8, r9, r10, r11, pc} \n\t"
: [newtcxt] "=m" (newt->cxt)
: [oldtcxt] "m" (oldt->cxt)
: "memory");
}
static __attribute__((pcs("aapcs-vfp"),naked)) void _gfxStartThread(thread *oldt, thread *newt) {
newt->cxt = (void *)(((unsigned)newt + newt->size) & ~7);
__asm__ volatile ( "push {r4, r5, r6, r7, r8, r9, r10, r11, lr} \n\t"
"vpush {s16-s31} \n\t"
"str sp, %[oldtcxt] \n\t"
"ldr sp, %[newtcxt] \n\t"
: [newtcxt] "=m" (newt->cxt)
: [oldtcxt] "m" (oldt->cxt)
: "memory");
// Run the users function
gfxThreadExit(_gfxCurrentThread->fn(_gfxCurrentThread->param));
}
#elif GFX_COMPILER == GFX_COMPILER_KEIL || GFX_COMPILER == GFX_COMPILER_ARMCC
#define GFX_THREADS_DONE
#define _gfxThreadsInit()
static __asm void _gfxTaskSwitch(thread *oldt, thread *newt) {
PRESERVE8
// Save the old context
push {r4, r5, r6, r7, r8, r9, r10, r11, lr}
vpush {s16-s31}
str sp, [r0,#__cpp(offsetof(thread,cxt))] // oldt->cxt
// Load the new context
ldr sp, [r1,#__cpp(offsetof(thread,cxt))] // newt->cxt
vpop {s16-s31}
pop {r4, r5, r6, r7, r8, r9, r10, r11, pc}
}
static __asm void _gfxStartThread(thread *oldt, thread *newt) {
PRESERVE8
// Calculate where to generate the new context
// newt->cxt = (void *)(((unsigned)newt + newt->size) & ~7);
ldr r2,[r1,#__cpp(offsetof(thread,size))]
add r2,r2,r1
and r2, r2, #0xFFFFFFF8
str r2,[r1,#__cpp(offsetof(thread,cxt))]
// Save the old context
push {r4, r5, r6, r7, r8, r9, r10, r11, lr}
vpush {s16-s31}
str sp, [r0,#__cpp(offsetof(thread,cxt))] // oldt->cxt
// Load the new (imcomplete) context
ldr sp, [r1,#__cpp(offsetof(thread,cxt))] // newt->cxt
// Run the users function - we save some code because gfxThreadExit() never returns
// gfxThreadExit(_gfxCurrentThread->fn(_gfxCurrentThread->param));
ldr r2,=__cpp(&_gfxCurrentThread)
ldr r2,[r2,#0]
ldr r0,[r2,#__cpp(offsetof(thread,param))]
ldr r1,[r2,#__cpp(offsetof(thread,fn))]
blx r1
mov r4,r0
bl __cpp(gfxThreadExit)
ALIGN
}
#else
#warning "GOS: Threads: You have specified a specific CPU but your compiler is not supported. Defaulting to CLIB switching"
#endif