src/soc/amd/picasso/psp_verstage/psp_verstage.c

/* SPDX-License-Identifier: GPL-2.0-only */

#include "psp_verstage.h"

#include <bl_uapp/bl_syscall_public.h>
#include <boot_device.h>
#include <cbfs.h>
#include <console/console.h>
#include <fmap.h>
#include <pc80/mc146818rtc.h>
#include <soc/psp_transfer.h>
#include <security/vboot/vbnv.h>
#include <security/vboot/misc.h>
#include <security/vboot/symbols.h>
#include <security/vboot/vboot_common.h>
#include <arch/stages.h>
#include <stdarg.h>
#include <stdio.h>

extern char _bss_start, _bss_end;
static struct mem_region_device boot_dev =
		MEM_REGION_DEV_RO_INIT(NULL, CONFIG_ROM_SIZE);

void __weak verstage_mainboard_early_init(void) {}
void __weak verstage_mainboard_init(void) {}

static void reboot_into_recovery(struct vb2_context *ctx, uint32_t subcode)
{
	subcode += PSP_VBOOT_ERROR_SUBCODE;
	svc_write_postcode(subcode);

	/*
	 * If there's an error but the PSP_verstage is already booting to RO,
	 * don't reset the system.  It may be that the error is fatal, but if
	 * the system is stuck, don't intentionally force it into a reboot loop.
	 */
	if (ctx->flags & VB2_CONTEXT_RECOVERY_MODE) {
		printk(BIOS_ERR, "Already in recovery mode. Staying in RO.\n");
		return;
	}

	vb2api_fail(ctx, VB2_RECOVERY_RO_UNSPECIFIED, (int)subcode);
	vboot_save_data(ctx);

	svc_debug_print("Rebooting into recovery\n");
	vboot_reboot();
}

static uint32_t check_cmos_recovery(void)
{
	/* Only reset if cmos is valid */
	if (vbnv_cmos_failed())
		return 0;

	/* If the byte is set, clear it, then return error to reboot */
	if (cmos_read(CMOS_RECOVERY_BYTE) == CMOS_RECOVERY_MAGIC_VAL) {
		cmos_write(0x00, CMOS_RECOVERY_BYTE);
		printk(BIOS_DEBUG, "Reboot into recovery requested by coreboot\n");
		return POSTCODE_CMOS_RECOVERY;
	}

	return 0;
}

static uintptr_t locate_amdfw(const char *name, struct region_device *rdev)
{
	struct cbfsf fh;
	uint32_t type = CBFS_TYPE_RAW;

	if (cbfs_locate(&fh, rdev, name, &type))
		return 0;

	cbfs_file_data(rdev, &fh);

	return (uintptr_t)rdev_mmap_full(rdev);
}

/*
 * Tell the PSP where to load the rest of the firmware from
 */
static uint32_t update_boot_region(struct vb2_context *ctx)
{
	struct psp_ef_table *ef_table;
	uint32_t psp_dir_addr, bios_dir_addr;
	uint32_t *psp_dir_in_spi, *bios_dir_in_spi;
	const char *rname, *fname;
	struct region_device rdev;
	uintptr_t amdfw_location;

	/* Continue booting from RO */
	if (ctx->flags & VB2_CONTEXT_RECOVERY_MODE) {
		printk(BIOS_ERR, "In recovery mode. Staying in RO.\n");
		return 0;
	}

	if (vboot_is_firmware_slot_a(ctx)) {
		rname = "FW_MAIN_A";
		fname = "apu/amdfw_a";
	} else {
		rname = "FW_MAIN_B";
		fname = "apu/amdfw_b";
	}

	if (fmap_locate_area_as_rdev(rname, &rdev)) {
		printk(BIOS_ERR, "Error: Could not locate fmap region %s.\n", rname);
		return POSTCODE_FMAP_REGION_MISSING;
	}

	amdfw_location = locate_amdfw(fname, &rdev);
	if (!amdfw_location) {
		printk(BIOS_ERR, "Error: AMD Firmware table not found.\n");
		return POSTCODE_AMD_FW_MISSING;
	}
	ef_table = (struct psp_ef_table *)amdfw_location;
	if (ef_table->signature != EMBEDDED_FW_SIGNATURE) {
		printk(BIOS_ERR, "Error: ROMSIG address is not correct.\n");
		return POSTCODE_ROMSIG_MISMATCH_ERROR;
	}

	psp_dir_addr = ef_table->psp_table;
	bios_dir_addr = ef_table->bios1_entry;
	psp_dir_in_spi = (uint32_t *)((psp_dir_addr & SPI_ADDR_MASK) +
			(uint32_t)boot_dev.base);
	bios_dir_in_spi = (uint32_t *)((bios_dir_addr & SPI_ADDR_MASK) +
			(uint32_t)boot_dev.base);
	if (*psp_dir_in_spi != PSP_COOKIE) {
		printk(BIOS_ERR, "Error: PSP Directory address is not correct.\n");
		return POSTCODE_PSP_COOKIE_MISMATCH_ERROR;
	}
	if (*bios_dir_in_spi != BDT1_COOKIE) {
		printk(BIOS_ERR, "Error: BIOS Directory address is not correct.\n");
		return POSTCODE_BDT1_COOKIE_MISMATCH_ERROR;
	}

	if (svc_update_psp_bios_dir((void *)&psp_dir_addr,
			(void *)&bios_dir_addr, DIR_OFFSET_SET)) {
		printk(BIOS_ERR, "Error: Updated BIOS Directory could not be set.\n");
		return POSTCODE_UPDATE_PSP_BIOS_DIR_ERROR;
	}

	return 0;
}

/*
 * Save workbuf (and soon memory console and timestamps) to the bootloader to pass
 * back to coreboot.
 */
static uint32_t save_buffers(struct vb2_context **ctx)
{
	uint32_t retval;
	uint32_t buffer_size = MIN_TRANSFER_BUFFER_SIZE;
	uint32_t max_buffer_size;
	struct transfer_info_struct buffer_info = {0};

	/*
	 * This should never fail, but if it does, we should still try to
	 * save the buffer. If that fails, then we should go to recovery mode.
	 */
	if (svc_get_max_workbuf_size(&max_buffer_size)) {
		post_code(POSTCODE_DEFAULT_BUFFER_SIZE_NOTICE);
		printk(BIOS_NOTICE, "Notice: using default transfer buffer size.\n");
		max_buffer_size = MIN_TRANSFER_BUFFER_SIZE;
	}
	printk(BIOS_DEBUG, "\nMaximum buffer size: %d bytes\n", max_buffer_size);

	/* Shrink workbuf if MP2 is in use and cannot be used to save buffer */
	if (max_buffer_size < VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE) {
		retval = vb2api_relocate(_vboot2_work, _vboot2_work, MIN_WORKBUF_TRANSFER_SIZE,
				ctx);
		if (retval != VB2_SUCCESS) {
			printk(BIOS_ERR, "Error shrinking workbuf. Error code %#x\n", retval);
			buffer_size = VB2_FIRMWARE_WORKBUF_RECOMMENDED_SIZE;
			post_code(POSTCODE_WORKBUF_RESIZE_WARNING);
		}
	} else {
		buffer_size =
			(uint32_t)((uintptr_t)_etransfer_buffer - (uintptr_t)_transfer_buffer);

		buffer_info.console_offset = (uint32_t)((uintptr_t)_preram_cbmem_console -
					(uintptr_t)_transfer_buffer);
		buffer_info.timestamp_offset = (uint32_t)((uintptr_t)_timestamp -
					(uintptr_t)_transfer_buffer);
		buffer_info.fmap_offset = (uint32_t)((uintptr_t)_fmap_cache -
					(uintptr_t)_transfer_buffer);
	}

	if (buffer_size > max_buffer_size) {
		printk(BIOS_ERR, "Error: Buffer is larger than max buffer size.\n");
		post_code(POSTCODE_WORKBUF_BUFFER_SIZE_ERROR);
		return POSTCODE_WORKBUF_BUFFER_SIZE_ERROR;
	}

	buffer_info.magic_val = TRANSFER_MAGIC_VAL;
	buffer_info.struct_bytes = sizeof(buffer_info);
	buffer_info.buffer_size = buffer_size;
	buffer_info.workbuf_offset = (uint32_t)((uintptr_t)_fmap_cache -
					(uintptr_t)_vboot2_work);

	memcpy(_transfer_buffer, &buffer_info, sizeof(buffer_info));

	retval = svc_save_uapp_data(UAPP_COPYBUF_CHROME_WORKBUF, (void *)_transfer_buffer,
				    buffer_size);
	if (retval) {
		printk(BIOS_ERR, "Error: Could not save workbuf. Error code 0x%08x\n", retval);
		return POSTCODE_WORKBUF_SAVE_ERROR;
	}

	return 0;
}

void Main(void)
{
	uint32_t retval;
	struct vb2_context *ctx = NULL;

	/*
	 * Do not use printk() before console_init()
	 * Do not use post_code() before verstage_mainboard_init()
	 */
	svc_write_postcode(POSTCODE_ENTERED_PSP_VERSTAGE);
	svc_debug_print("Entering verstage on PSP\n");
	memset(&_bss_start, '\0', &_bss_end - &_bss_start);

	svc_write_postcode(POSTCODE_CONSOLE_INIT);
	console_init();

	svc_write_postcode(POSTCODE_EARLY_INIT);
	retval = verstage_soc_early_init();
	if (retval) {
		svc_debug_print("verstage_soc_early_init failed\n");
		reboot_into_recovery(NULL, retval);
	}
	svc_debug_print("calling verstage_mainboard_early_init\n");

	verstage_mainboard_early_init();

	svc_write_postcode(POSTCODE_LATE_INIT);
	sb_enable_legacy_io();
	verstage_soc_init();
	verstage_mainboard_init();

	post_code(POSTCODE_VERSTAGE_MAIN);

	verstage_main();

	ctx = vboot_get_context();
	retval = check_cmos_recovery();
	if (retval)
		reboot_into_recovery(ctx, retval);

	post_code(POSTCODE_SAVE_BUFFERS);
	retval = save_buffers(&ctx);
	if (retval)
		reboot_into_recovery(ctx, retval);

	post_code(POSTCODE_UPDATE_BOOT_REGION);
	retval = update_boot_region(ctx);
	if (retval)
		reboot_into_recovery(ctx, retval);

	post_code(POSTCODE_UNMAP_SPI_ROM);
	if (boot_dev.base) {
		if (svc_unmap_spi_rom((void *)boot_dev.base))
			printk(BIOS_ERR, "Error unmapping SPI rom\n");
	}

	post_code(POSTCODE_UNMAP_FCH_DEVICES);
	unmap_fch_devices();

	post_code(POSTCODE_LEAVING_VERSTAGE);

	printk(BIOS_DEBUG, "Leaving verstage on PSP\n");
	svc_exit(retval);
}

const struct region_device *boot_device_ro(void)
{
	uintptr_t *addr;

	addr = map_spi_rom();
	mem_region_device_ro_init(&boot_dev, (void *)addr, CONFIG_ROM_SIZE);

	return &boot_dev.rdev;
}

/*
 * The stage_entry function is not used directly, but stage_entry() is marked as an entry
 * point in arm/arch/header.h, so if stage_entry() isn't present and calling Main(), all
 * the verstage code gets dropped by the linker.  Slightly hacky, but mostly harmless.
 */
void stage_entry(uintptr_t stage_arg)
{
	Main();
}