system76-coreboot/src/include/program_loading.h

/*
 * This file is part of the coreboot project.
 *
 * Copyright 2015 Google Inc.
 * Copyright (C) 2014 Imagination Technologies
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#ifndef PROGRAM_LOADING_H
#define PROGRAM_LOADING_H

#include <commonlib/region.h>
#include <stdint.h>
#include <stddef.h>

enum {
	/* Last segment of program. Can be used to take different actions for
	 * cache maintenance of a program load. */
	SEG_FINAL = 1 << 0,
};

// The prog_type is a bit mask, so that in searches one can find, e.g.,
// a file with a given name that is either a payload or a ramstage.
// The PROG_UNKNOWN should not have any bits set that match a valid
// type, and for the sake of sanity, let's keep the high order bit out of it.
// The current value allows for 16 file types. This is a change from before,
// where we could have 2^32-1 different types. On a guess, it seems 16 should
// be enough. We started with 3 and are up to 6 twelve years later.
enum prog_type {
	PROG_UNKNOWN = 0x7bba0000,
	PROG_VERSTAGE = 1 << 0,
	PROG_ROMSTAGE = 1 << 1,
	PROG_RAMSTAGE = 1 << 2,
	PROG_REFCODE = 1 << 3,
	PROG_PAYLOAD = 1 << 4,
	PROG_BL31 = 1 << 5,
	PROG_BL32 = 1 << 6,
};

/*
 * prog_segment_loaded() is called for each segment of a program loaded. The
 * SEG_FINAL flag will be set on the last segment loaded. The following two
 * functions, platform_segment_loaded() and arch_segment_loaded(), are called
 * in that order within prog_segment_loaded(). In short, rely on
 * prog_segment_loaded() to perform the proper dispatch sequence.
 */
void prog_segment_loaded(uintptr_t start, size_t size, int flags);
void platform_segment_loaded(uintptr_t start, size_t size, int flags);
void arch_segment_loaded(uintptr_t start, size_t size, int flags);

/* Return true if arch supports bounce buffer.  */
int arch_supports_bounce_buffer(void);

/* Representation of a program. */
struct prog {
	/* The region_device is the source of program content to load. After
	 * loading program it represents the memory region of the stages and
	 * payload. For architectures that use a bounce buffer
	 * then it would represent the bounce buffer. */
	enum prog_type type;
	uint32_t cbfs_type;
	const char *name;
	struct region_device rdev;
	/* Entry to program with optional argument. It's up to the architecture
	 * to decide if argument is passed. */
	void (*entry)(void *);
	void *arg;
};

#define PROG_INIT(type_, name_)				\
	{						\
		.type = (type_),			\
		.name = (name_),			\
	}

static inline const char *prog_name(const struct prog *prog)
{
	return prog->name;
}

static inline enum prog_type prog_type(const struct prog *prog)
{
	return prog->type;
}

static inline uint32_t prog_cbfs_type(const struct prog *prog)
{
	return prog->cbfs_type;
}

static inline struct region_device *prog_rdev(struct prog *prog)
{
	return &prog->rdev;
}

/* Only valid for loaded programs. */
static inline size_t prog_size(const struct prog *prog)
{
	return region_device_sz(&prog->rdev);
}

/* Only valid for loaded programs. */
static inline void *prog_start(const struct prog *prog)
{
	return rdev_mmap_full(&prog->rdev);
}

static inline void *prog_entry(const struct prog *prog)
{
	return prog->entry;
}

static inline void *prog_entry_arg(const struct prog *prog)
{
	return prog->arg;
}

/* region_device representing the 32-bit flat address space. */
extern const struct mem_region_device addrspace_32bit;

static inline void prog_memory_init(struct prog *prog, uintptr_t ptr,
					size_t size)
{
	rdev_chain(&prog->rdev, &addrspace_32bit.rdev, ptr, size);
}

static inline void prog_set_area(struct prog *prog, void *start, size_t size)
{
	prog_memory_init(prog, (uintptr_t)start, size);
}

static inline void prog_set_entry(struct prog *prog, void *e, void *arg)
{
	prog->entry = e;
	prog->arg = arg;
}

/* Locate the identified program to run. Return 0 on success. < 0 on error. */
int prog_locate(struct prog *prog);

/* Run the program described by prog. */
void prog_run(struct prog *prog);
/* Per architecture implementation running a program. */
void arch_prog_run(struct prog *prog);
/* Platform (SoC/chipset) specific overrides for running a program. This is
 * called prior to calling the arch_prog_run. Thus, if there is anything
 * special that needs to be done by the platform similar to the architecture
 * code it needs to that as well. */
void platform_prog_run(struct prog *prog);

struct prog_loader_ops {
	const char *name;
	/* Determine if the loader is the active one. If so returns 1 else 0
	 * or < 0 on error. */
	int (*is_loader_active)(struct prog *prog);
	/* Returns < 0 on error or 0 on success. This function locates
	 * the rdev representing the file data associated with the passed in
	 * prog. */
	int (*locate)(struct prog *prog);
};

/************************
 *   ROMSTAGE LOADING   *
 ************************/

/* Run romstage from bootblock. */
void run_romstage(void);

/************************
 *   RAMSTAGE LOADING   *
 ************************/

/* Run ramstage from romstage. */
void run_ramstage(void);

/* Determine where stack for ramstage loader is located. */
enum { ROMSTAGE_STACK_CBMEM, ROMSTAGE_STACK_LOW_MEM };
uintptr_t romstage_ram_stack_base(size_t size, int src);
uintptr_t romstage_ram_stack_top(void);
uintptr_t romstage_ram_stack_bottom(void);

/* Backup OS memory to CBMEM_ID_RESUME on ACPI S3 resume path,
 * if ramstage overwrites low memory. */
void backup_ramstage_section(uintptr_t base, size_t size);

/***********************
 *   PAYLOAD LOADING   *
 ***********************/

/* Load payload into memory in preparation to run. */
void payload_load(void);

/* Run the loaded payload. */
void payload_run(void);

/* Mirror the payload to be loaded. */
void mirror_payload(struct prog *payload);

/*
 * Set check_regions to true to check that the payload targets usable memory.
 * With this flag set, if it does not, the load will fail and this function
 * will return NULL.
 *
 * Defined in src/lib/selfboot.c
 */
void *selfload(struct prog *payload, bool check_regions);

#endif /* PROGRAM_LOADING_H */