[U-Boot] [PATCH 57/69] x86: broadwell: Add reference code support

[Bin Meng]

Hi Simon,

On Mon, Mar 7, 2016 at 10:28 AM, Simon Glass <sjg at chromium.org> wrote:
> Broadwell needs a special binary blob to set up the PCH. Add code to run
> this on start-up.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  arch/x86/cpu/broadwell/Makefile  |   1 +
>  arch/x86/cpu/broadwell/refcode.c | 108 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 109 insertions(+)
>  create mode 100644 arch/x86/cpu/broadwell/refcode.c
>
> diff --git a/arch/x86/cpu/broadwell/Makefile b/arch/x86/cpu/broadwell/Makefile
> index 3054a89..a542fef 100644
> --- a/arch/x86/cpu/broadwell/Makefile
> +++ b/arch/x86/cpu/broadwell/Makefile
> @@ -10,4 +10,5 @@ obj-y += lpc.o
>  obj-y += northbridge.o
>  obj-y += pch.o
>  obj-y += pinctrl_broadwell.o
> +obj-y += refcode.o
>  obj-y += sata.o
> diff --git a/arch/x86/cpu/broadwell/refcode.c b/arch/x86/cpu/broadwell/refcode.c
> new file mode 100644
> index 0000000..8c1d99c
> --- /dev/null
> +++ b/arch/x86/cpu/broadwell/refcode.c
> @@ -0,0 +1,108 @@
> +/*
> + * Read a coreboot rmodule and execute it.
> + * The rmodule_header struct is from coreboot.
> + *
> + * Copyright (c) 2016 Google, Inc
> + *
> + * SPDX-License-Identifier:    GPL-2.0

nits: GPL-2.0+

> + */
> +
> +#include <common.h>
> +#include <errno.h>
> +#include <asm/arch/pei_data.h>
> +
> +#define RMODULE_MAGIC          0xf8fe
> +#define RMODULE_VERSION_1      1
> +
> +/*
> + * All fields with '_offset' in the name are byte offsets into the flat blob.
> + * The linker and the linker script takes are of assigning the values.
> + */
> +struct rmodule_header {
> +       uint16_t magic;
> +       uint8_t  version;
> +       uint8_t  type;
> +       /* The payload represents the program's loadable code and data. */

nits: remove ending .

> +       uint32_t payload_begin_offset;
> +       uint32_t payload_end_offset;
> +       /* Begin and of relocation information about the program module. */

nits: remove ending .

> +       uint32_t relocations_begin_offset;
> +       uint32_t relocations_end_offset;
> +       /* The starting address of the linked program. This address is vital
> +        * for determining relocation offsets as the relocation info and other
> +        * symbols (bss, entry point) need this value as a basis to calculate
> +        * the offsets.
> +        */

nits: please use correct multi-line comment format.

> +       uint32_t module_link_start_address;
> +       /* The module_program_size is the size of memory used while running
> +        * the program. The program is assumed to consume a contiguous amount
> +        * of memory. */

ditto.

> +       uint32_t module_program_size;
> +       /* This is program's execution entry point. */

nits: remove ending .

> +       uint32_t module_entry_point;
> +       /* Optional parameter structure that can be used to pass data into
> +        * the module. */

nits: please use correct multi-line comment format.

> +       uint32_t parameters_begin;
> +       uint32_t parameters_end;
> +       /* BSS section information so the loader can clear the bss. */

nits: remove ending .

> +       uint32_t bss_begin;
> +       uint32_t bss_end;
> +       /* Add some room for growth. */

nits: remove ending .

> +       uint32_t padding[4];
> +} __packed;
> +
> +int cpu_run_reference_code(void)
> +{
> +       struct pei_data _pei_data __aligned(8);
> +       struct pei_data *pei_data = &_pei_data;
> +       asmlinkage int (*func)(void *);
> +       struct rmodule_header *hdr;
> +       char *src, *dest;
> +       int ret, dummy;
> +       int size;
> +
> +       hdr = (struct rmodule_header *)CONFIG_X86_REFCODE_ADDR;
> +       debug("Extracting code from rmodule at %p\n", hdr);
> +       if (hdr->magic != RMODULE_MAGIC) {
> +               debug("Invalid rmodule magic\n");
> +               return -EINVAL;
> +       }
> +       if (hdr->module_link_start_address != 0) {
> +               debug("Link start address must be 0\n");
> +               return -EPERM;
> +       }
> +       if (hdr->module_entry_point != 0) {
> +               debug("Entry point must be 0\n");
> +               return -EPERM;
> +       }
> +
> +       memset(pei_data, '\0', sizeof(struct pei_data));
> +       broadwell_fill_pei_data(pei_data);
> +       mainboard_fill_pei_data(pei_data);
> +       pei_data->saved_data = (void *)&dummy;
> +
> +       src = (char *)hdr + hdr->payload_begin_offset;
> +       dest = (char *)CONFIG_X86_REFCODE_RUN_ADDR;
> +
> +       size = hdr->payload_end_offset - hdr->payload_begin_offset;
> +       debug("Copying refcode from %p to %p, size %x\n", src, dest, size);
> +       memcpy(dest, src, size);
> +
> +       size = hdr->bss_end - hdr->bss_begin;
> +       debug("Zeroing BSS at %p, size %x\n", dest + hdr->bss_begin, size);
> +       memset(dest + hdr->bss_begin, '\0', size);
> +
> +       func = (asmlinkage int (*)(void *))dest;
> +       debug("Running reference code at %p\n", func);
> +#ifdef DEBUG
> +       print_buffer(CONFIG_X86_REFCODE_RUN_ADDR, (void *)func, 1, 0x40, 0);
> +#endif
> +       ret = func(pei_data);
> +       if (ret != 0) {
> +               debug("Reference code returned %d\n", ret);
> +               return -EL2HLT;
> +       }
> +       debug("Refereence code completed\n");
> +
> +       return 0;
> +}
> --

Regards,
Bin