/**
 * \file
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 *
 * \brief Cortex-M3 context switch
 *
 * \author Andrea Righi <arighi@develer.com>
 */

.syntax unified

/* void asm_switch_context(void **new_sp [r0], void **save_sp [r1]) */
.global asm_switch_context
.thumb_func
asm_switch_context:
	mrs r12, msp
        /* Save registers */
	stmdb r12!, {r4-r11, lr}
        /* Save old stack pointer */
	str r12, [r1]
        /* Load new stack pointer */
	ldr r12, [r0]
        /* Load new registers */
	ldmia r12!, {r4-r11, lr}
	msr msp, r12
	bx lr