src/boot_flow/linux.c

/*
 * Copyright 2019 The Hafnium Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "hf/cpio.h"
#include "hf/dlog.h"
#include "hf/fdt_handler.h"
#include "hf/plat/boot_flow.h"
#include "hf/std.h"

/**
 * Looks for a file in the given cpio archive. The file, if found, is returned
 * in the "it" argument.
 */
static bool find_file(const struct memiter *cpio, const char *name,
		      struct memiter *it)
{
	const char *fname;
	const void *fcontents;
	size_t fsize;
	struct memiter iter = *cpio;

	while (cpio_next(&iter, &fname, &fcontents, &fsize)) {
		if (!strcmp(fname, name)) {
			memiter_init(it, fcontents, fsize);
			return true;
		}
	}

	return false;
}

/* Set by arch-specific boot-time hook. */
uintreg_t plat_boot_flow_fdt_addr;

/**
 * Returns the physical address of board FDT. This was passed to Hafnium in the
 * first kernel arg by the boot loader.
 */
paddr_t plat_boot_flow_get_fdt_addr(void)
{
	return pa_init((uintpaddr_t)plat_boot_flow_fdt_addr);
}

/**
 * When handing over to the primary, give it the same FDT address that was given
 * to Hafnium. The FDT may have been modified during Hafnium init.
 */
uintreg_t plat_boot_flow_get_kernel_arg(void)
{
	return plat_boot_flow_fdt_addr;
}

/**
 * Load initrd range from the board FDT.
 */
bool plat_boot_flow_get_initrd_range(const struct fdt_node *fdt_root,
				     paddr_t *begin, paddr_t *end)
{
	return fdt_find_initrd(fdt_root, begin, end);
}

bool plat_boot_flow_update(struct mm_stage1_locked stage1_locked,
			   struct boot_params_update *update,
			   struct memiter *cpio, struct mpool *ppool)
{
	struct memiter primary_initrd;

	if (!find_file(cpio, "initrd.img", &primary_initrd)) {
		dlog("Unable to find initrd.img\n");
		return false;
	}

	update->initrd_begin = pa_from_va(va_from_ptr(primary_initrd.next));
	update->initrd_end = pa_from_va(va_from_ptr(primary_initrd.limit));

	return fdt_patch(stage1_locked, plat_boot_flow_get_fdt_addr(), update,
			 ppool);
}