github.com/usbarmory/tamago@v0.0.0-20240508072735-8612bbe1e454/arm/tz.s (about)

     1  // ARM processor support
     2  // https://github.com/usbarmory/tamago
     3  //
     4  // Copyright (c) WithSecure Corporation
     5  // https://foundry.withsecure.com
     6  //
     7  // Use of this source code is governed by the license
     8  // that can be found in the LICENSE file.
     9  
    10  // func read_scr() uint32
    11  TEXT ·read_scr(SB),$0-4
    12  	// ARM Architecture Reference Manual - ARMv7-A and ARMv7-R edition
    13  	// B4.1.129 SCR, Secure Configuration Register, Security Extensions
    14  	MRC	15, 0, R0, C1, C1, 0
    15  	MOVW	R0, ret+0(FP)
    16  
    17  	RET
    18  
    19  // func write_nsacr(scr uint32)
    20  TEXT ·write_nsacr(SB),$0-4
    21  	// ARM Architecture Reference Manual - ARMv7-A and ARMv7-R edition
    22  	// B4.1.111 NSACR, Non-Secure Access Control Register, Security Extensions
    23  	MOVW	scr+0(FP), R0
    24  	MCR	15, 0, R0, C1, C1, 2
    25  
    26  	RET