Hi Simon,
Thanks for your work on this! It's nice to see that you can actually
load some data early on.
On Sat, Nov 27, 2010 at 8:05 AM, Simon Horman <horms@xxxxxxxxxxxx> wrote:
> This is a prototype of code to read the MMCIF during
> zboot initialisation. The intention is that it will form
> part of enabling booting from MMC. Very roughly the plan is
>
> 1) The Mask Rom will load a small boot program from MMC.
> Essentially this will be the first portion of
> the kernel to be booted.
> 2) That program will load the remainder of the kernel
> from MMC and boot from it.
>
> This patch demonstrates code to perform the read portion of 2).
> It uses a dummy buffer and only reads in one 512 byte sector.
> A full implementation of 2) would of course read much more.
>
> The patch currently hooks into head-shmobile.S as it
> depends on initialisation that occurs in that file.
> However, it is likely that the final implementation
> will need to be located in head.S where relocation is
> currently handled.
>
> I used a multi-voltage MMC mobile card to test this code.
> I observed that a single-voltage MMC and MMCplus card caused
> the code to time-out in sh_mmcif_boot_init() which causes
> the boot to stop.
>
> This patch depends on "ARM: mach-shmobile: Add zboot support for SuperH
> Mobile ARM" and "mmc, sh: Correct value for reset".
>
> Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx>
> ---
> arch/arm/boot/compressed/Makefile | 4 +
> arch/arm/boot/compressed/head-shmobile.S | 16 +++++
> arch/arm/boot/compressed/mmcif-sh7372.c | 100 ++++++++++++++++++++++++++++++
> 3 files changed, 120 insertions(+), 0 deletions(-)
> create mode 100644 arch/arm/boot/compressed/mmcif-sh7372.c
>
> diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
> index 0a8f748..f730c10 100644
> --- a/arch/arm/boot/compressed/Makefile
> +++ b/arch/arm/boot/compressed/Makefile
> @@ -49,6 +49,10 @@ ifeq ($(CONFIG_ARCH_SHMOBILE),y)
> OBJS += head-shmobile.o
> endif
>
> +ifeq ($(CONFIG_ARCH_SH7372),y)
> +OBJS += mmcif-sh7372.o
> +endif
> +
> #
> # We now have a PIC decompressor implementation. Decompressors running
> # from RAM should not define ZTEXTADDR. Decompressors running directly
> diff --git a/arch/arm/boot/compressed/head-shmobile.S b/arch/arm/boot/compressed/head-shmobile.S
> index 30973b7..700d622 100644
> --- a/arch/arm/boot/compressed/head-shmobile.S
> +++ b/arch/arm/boot/compressed/head-shmobile.S
> @@ -26,6 +26,22 @@
> #include <mach/zboot.h>
>
> b 1f
> + .align
> +__tmp_stack:
> + .space 128
> +__dummy_buf:
> + .space 512
> +__dummy_buf_size:
> + .long 512
> +1:
> + adr sp, __tmp_stack
> + add sp, sp, #128
> + adr r0, __dummy_buf
> + ldr r1, __dummy_buf_size
Regarding the destination address, look into using CONFIG_MEMORY_START
or perhaps something more advanced like the actual destination address
for the kernel - see arch/arm/boot/compressed/head.S and TEXT_OFFSET
or zreladdr.
As for the number of bytes to load, please have a look at the sh7724
implementation.
> + mov lr, pc
> + b mmcif_loader
> +
> + b 1f
> __atags:@ tag #1
> .long 12 @ tag->hdr.size = tag_size(tag_core);
> .long 0x54410001 @ tag->hdr.tag = ATAG_CORE;
> diff --git a/arch/arm/boot/compressed/mmcif-sh7372.c b/arch/arm/boot/compressed/mmcif-sh7372.c
> new file mode 100644
> index 0000000..7ffaf27
> --- /dev/null
> +++ b/arch/arm/boot/compressed/mmcif-sh7372.c
> @@ -0,0 +1,100 @@
> +/*
> + * sh7372 MMCIF loader
> + *
> + * Copyright (C) 2010 Magnus Damm
> + * Copyright (C) 2010 Simon Horman
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License. See the file "COPYING" in the main directory of this archive
> + * for more details.
> + */
> +
> +#include <linux/mmc/sh_mmcif.h>
> +
> +#define MMCIF_BASE (void __iomem *)0xe6bd0000
> +
> +#define PORT84CR 0xe6050054
> +#define PORT85CR 0xe6050055
> +#define PORT86CR 0xe6050056
> +#define PORT87CR 0xe6050057
> +#define PORT88CR 0xe6050058
> +#define PORT89CR 0xe6050059
> +#define PORT90CR 0xe605005a
> +#define PORT91CR 0xe605005b
> +#define PORT92CR 0xe605005c
> +#define PORT99CR 0xe6050063
> +#define PORT185CR 0xe60520b9
> +#define PORT186CR 0xe60520ba
> +#define PORT187CR 0xe60520bb
> +#define PORT188CR 0xe60520bc
> +#define PORTR191_160DR 0xe6056014
> +
> +#define SMSTPCR3 0xe615013c
> +
> +enum { MMCIF_PROGRESS_ENTER, MMCIF_PROGRESS_INIT,
> + MMCIF_PROGRESS_LOAD, MMCIF_PROGRESS_DONE };
> +
> +static void mmcif_update_progress(int n)
> +{
> + __raw_writel((__raw_readl(PORTR191_160DR) & ~(0xf << 25)) |
> + (1 << (25 + n)), PORTR191_160DR);
> +}
This seems like a board specific property to me. So please break it
out in to a per-board header or similar.
I guess next step is to extend the prototype code so it loads the
entire kernel from MMC and then jumps to it. =)
Cheers,
/ magnus
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
