Re: [PATCH v2 02/29] nios2: Kernel booting and initialization

Tobias Klauser
2014-07-30T09:12:21Z

On 2014-07-15 at 10:45:29 +0200, Ley Foon Tan <lftan@altera.com> wrote:
> This patch adds the kernel booting and the initial setup code.
>
> Signed-off-by: Ley Foon Tan <lftan@altera.com>
> ---
> arch/nios2/include/asm/entry.h | 152 ++++++++++++++++++++++++++++
> arch/nios2/include/asm/setup.h | 38 +++++++
> arch/nios2/kernel/head.S | 175 ++++++++++++++++++++++++++++++++
> arch/nios2/kernel/setup.c | 222 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 587 insertions(+)
> create mode 100644 arch/nios2/include/asm/entry.h
> create mode 100644 arch/nios2/include/asm/setup.h
> create mode 100644 arch/nios2/kernel/head.S
> create mode 100644 arch/nios2/kernel/setup.c
>
> diff --git a/arch/nios2/include/asm/entry.h b/arch/nios2/include/asm/entry.h
> new file mode 100644
> index 0000000..8b7cddd
> --- /dev/null
> +++ b/arch/nios2/include/asm/entry.h
> @@ -0,0 +1,152 @@

[...]

> +/*
> + * Stack layout in 'ret_from_exception':
> + *
> + * This allows access to the syscall arguments in registers r4-r8
> + *
> + * 0(sp) - r8
> + * 4(sp) - r9
> + * 8(sp) - r10
> + * C(sp) - r11
> + * 10(sp) - r12
> + * 14(sp) - r13
> + * 18(sp) - r14
> + * 1C(sp) - r15
> + * 20(sp) - r1
> + * 24(sp) - r2
> + * 28(sp) - r3
> + * 2C(sp) - r4
> + * 30(sp) - r5
> + * 34(sp) - r6
> + * 38(sp) - r7
> + * 3C(sp) - orig_r2
> + * 40(sp) - ra
> + * 44(sp) - fp
> + * 48(sp) - sp
> + * 4C(sp) - gp
> + * 50(sp) - estatus
> + * 54(sp) - status_extension (NOMMU only)
> + * 58(sp) - ea
> + */

status_extension no longer exists and orig_r7 is missing in the list
above. Since this corresponds to the order of struct pt_regs anyhow,
this comment seems rather pointless to me, so you might as well want to
remove it altogether.