[U-Boot] [PATCH v2 3/7] ARM: add assembly routine to switch to non-secure state

[Masahiro Yamada]

Hi, Andre


> +.globl _nonsec_init
> +_nonsec_init:

These two lines can be written:

ENTRY(_nonsec_init)



> +	mrc	p15, 0, r0, c0, c0, 0		@ read MIDR
> +	bfc	r0, #20, #4			@ mask out variant
> +	bfc	r0, #0, #4			@ and revision

Why do you hard code bit positions
even though MIDR_PRIMARY_PART_MASK is available?

> +	movw	r1, #lo(MIDR_CORTEX_A7_R0P0 & MIDR_PRIMARY_PART_MASK)
> +	movt	r1, #hi(MIDR_CORTEX_A7_R0P0 & MIDR_PRIMARY_PART_MASK)

Why don't you use "ldr   r*, =..." statement here?

> +	orr	r1, #(MIDR_CORTEX_A15_R0P0 & 0xf0)

This code relies on  the value of MIDR_CORTEX_A15_R0P0.



So, I think you can rewrite this part more simply as follows:


	mrc	p15, 0, r0, c0, c0, 0		@ read MIDR
	ldr	r1, =MIDR_PRIMARY_PART_MASK
	and     r0, r0, r1 			@ mask out variant and revision

	ldr	r1, =MIDR_CORTEX_A7_R0P0
	cmp	r0, r1				@ check for Cortex-A7

	ldr	r1, =MIDR_CORTEX_A15_R0P0
	cmpne	r0, r1				@ check for Cortex-A15




> +	bx	lr

Add ENDPROC(_nonsec_init) when beginning with ENTRY(_nonsec_init).


> +/* defined in cpu/armv7/nonsec_virt.S */
> +void _nonsec_init(void);

I think this comment is not necessary and
mantainancability is not excellent in case you renaming
nonsec_virt.S.


BTW, tag generation tool, GNU Global can help us
for searching definition.

If you begin routines in assembly with ENTRY(...),
GNU Global picks up these symbols for tag jump.



Masahiro Yamada