[U-Boot] [PATCH 06/14] efi_loader: Add runtime services

[Leif Lindholm]

On Fri, Jan 15, 2016 at 06:06:12AM +0100, Alexander Graf wrote:
> After booting has finished, EFI allows firmware to still interact with the OS
> using the "runtime services". These callbacks live in a separate address space,
> since they are available long after U-Boot has been overwritten by the OS.
> 
> This patch adds enough framework for arbitrary code inside of U-Boot to become
> a runtime service with the right section attributes set. For now, we don't make
> use of it yet though.
> 
> We could maybe in the future map U-boot environment variables to EFI variables
> here.
> 
> Signed-off-by: Alexander Graf <agraf at suse.de>

Just a couple of return value issues:

> ---
> 
> v1 -> v2:
> 
>   - Fix runtime service sections
>   - Add runtime detach
>   - Enable runtime relocations
>   - Add get_time
>   - Fix relocation
>   - Fix 32bit
>   - Add am335x support
>   - Move section definition to header
>   - Add systab to runtime section
>   - Add self-relocation hook table
>   - Fix self-relocation
>   - Relocate efi_runtime section early during bootup
>   - Fix return values for a number of callbacks to be more UEFI compliant
>   - Move to GPLv2+
> ---
>  arch/arm/config.mk            |   4 +
>  arch/arm/cpu/armv8/u-boot.lds |  16 +++
>  arch/arm/cpu/u-boot.lds       |  30 +++++
>  arch/arm/lib/sections.c       |   4 +
>  board/ti/am335x/u-boot.lds    |  30 +++++
>  common/board_r.c              |   4 +
>  include/efi_loader.h          |  10 ++
>  lib/efi_loader/efi_boottime.c |   6 +-
>  lib/efi_loader/efi_runtime.c  | 300 ++++++++++++++++++++++++++++++++++++++++++
>  9 files changed, 401 insertions(+), 3 deletions(-)
>  create mode 100644 lib/efi_loader/efi_runtime.c
> 

...

> diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
> new file mode 100644
> index 0000000..b7aa1e9
> --- /dev/null
> +++ b/lib/efi_loader/efi_runtime.c
> @@ -0,0 +1,300 @@
> +/*
> + *  EFI application runtime services
> + *
> + *  Copyright (c) 2016 Alexander Graf
> + *
> + *  SPDX-License-Identifier:     GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <efi_loader.h>
> +#include <command.h>
> +#include <asm/global_data.h>
> +#include <rtc.h>
> +
> +/* For manual relocation support */
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +static efi_status_t EFI_RUNTIME_TEXT efi_unimplemented(void);
> +static efi_status_t EFI_RUNTIME_TEXT efi_device_error(void);
> +static efi_status_t EFI_RUNTIME_TEXT efi_invalid_parameter(void);
> +
> +#if defined(CONFIG_ARM64)
> +#define R_RELATIVE	1027
> +#define R_MASK		0xffffffffULL
> +#define IS_RELA		1
> +#elif defined(CONFIG_ARM)
> +#define R_RELATIVE	23
> +#define R_MASK		0xffULL
> +#else
> +#error Need to add relocation awareness
> +#endif
> +
> +struct elf_rel {
> +	ulong *offset;
> +	ulong info;
> +};
> +
> +struct elf_rela {
> +	ulong *offset;
> +	ulong info;
> +	long addend;
> +};
> +
> +/*
> + * EFI Runtime code lives in 2 stages. In the first stage, U-Boot and an EFI
> + * payload are running concurrently at the same time. In this mode, we can
> + * handle a good number of runtime callbacks
> + */
> +
> +static void efi_reset_system(enum efi_reset_type reset_type,
> +			efi_status_t reset_status, unsigned long data_size,
> +			void *reset_data)
> +{
> +	EFI_ENTRY("%d %lx %lx %p", reset_type, reset_status, data_size, reset_data);
> +
> +	switch (reset_type) {
> +	case EFI_RESET_COLD:
> +	case EFI_RESET_WARM:
> +		do_reset(NULL, 0, 0, NULL);
> +		break;
> +	case EFI_RESET_SHUTDOWN:
> +		/* We don't have anything to map this to */
> +		break;
> +	}
> +
> +	EFI_EXIT(EFI_SUCCESS);
> +}
> +
> +static efi_status_t efi_get_time(struct efi_time *time,
> +			  struct efi_time_cap *capabilities)
> +{
> +#ifdef CONFIG_CMD_DATE
> +
> +	struct rtc_time tm;
> +	int r;
> +#ifdef CONFIG_DM_RTC
> +	struct udevice *dev;
> +#endif
> +
> +	EFI_ENTRY("%p %p", time, capabilities);
> +
> +#ifdef CONFIG_DM_RTC
> +	r = uclass_get_device(UCLASS_RTC, 0, &dev);
> +	if (r)
> +		return EFI_EXIT(EFI_UNSUPPORTED);

EFI_DEVICE_ERROR?

> +#endif
> +
> +#ifdef CONFIG_DM_RTC
> +	r = dm_rtc_get(dev, &tm);
> +#else
> +	r = rtc_get(&tm);
> +#endif
> +	if (r)
> +		return EFI_EXIT(EFI_UNSUPPORTED);

EFI_DEVICE_ERROR?

> +
> +	memset(time, 0, sizeof(*time));
> +	time->year = tm.tm_year;
> +	time->month = tm.tm_mon;
> +	time->day = tm.tm_mday;
> +	time->hour = tm.tm_hour;
> +	time->minute = tm.tm_min;
> +	time->daylight = tm.tm_isdst;
> +
> +	return EFI_EXIT(EFI_SUCCESS);
> +
> +#else /* CONFIG_CMD_DATE */
> +
> +	return EFI_DEVICE_ERROR;
> +
> +#endif /* CONFIG_CMD_DATE */
> +}