boot.c

/*
 * QEMU RISC-V Boot Helper
 *
 * Copyright (c) 2017 SiFive, Inc.
 * Copyright (c) 2019 Alistair Francis <alistair.francis@wdc.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2 or later, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "qemu/osdep.h"
#include "qemu/datadir.h"
#include "qemu/units.h"
#include "qemu/error-report.h"
#include "exec/cpu-defs.h"
#include "hw/boards.h"
#include "hw/loader.h"
#include "hw/riscv/boot.h"
#include "hw/riscv/boot_opensbi.h"
#include "elf.h"
#include "sysemu/device_tree.h"
#include "sysemu/qtest.h"
#include "sysemu/kvm.h"

#include <libfdt.h>

bool riscv_is_32bit(RISCVHartArrayState *harts)
{
    return harts->harts[0].env.misa_mxl_max == MXL_RV32;
}

/*
 * Return the per-socket PLIC hart topology configuration string
 * (caller must free with g_free())
 */
char *riscv_plic_hart_config_string(int hart_count)
{
    g_autofree const char **vals = g_new(const char *, hart_count + 1);
    int i;

    for (i = 0; i < hart_count; i++) {
        CPUState *cs = qemu_get_cpu(i);
        CPURISCVState *env = &RISCV_CPU(cs)->env;

        if (kvm_enabled()) {
            vals[i] = "S";
        } else if (riscv_has_ext(env, RVS)) {
            vals[i] = "MS";
        } else {
            vals[i] = "M";
        }
    }
    vals[i] = NULL;

    /* g_strjoinv() obliges us to cast away const here */
    return g_strjoinv(",", (char **)vals);
}

target_ulong riscv_calc_kernel_start_addr(RISCVHartArrayState *harts,
                                          target_ulong firmware_end_addr) {
    if (riscv_is_32bit(harts)) {
        return QEMU_ALIGN_UP(firmware_end_addr, 4 * MiB);
    } else {
        return QEMU_ALIGN_UP(firmware_end_addr, 2 * MiB);
    }
}

target_ulong riscv_find_and_load_firmware(MachineState *machine,
                                          const char *default_machine_firmware,
                                          hwaddr firmware_load_addr,
                                          symbol_fn_t sym_cb)
{
    char *firmware_filename = NULL;
    target_ulong firmware_end_addr = firmware_load_addr;

    if ((!machine->firmware) || (!strcmp(machine->firmware, "default"))) {
        /*
         * The user didn't specify -bios, or has specified "-bios default".
         * That means we are going to load the OpenSBI binary included in
         * the QEMU source.
         */
        firmware_filename = riscv_find_firmware(default_machine_firmware);
    } else if (strcmp(machine->firmware, "none")) {
        firmware_filename = riscv_find_firmware(machine->firmware);
    }

    if (firmware_filename) {
        /* If not "none" load the firmware */
        firmware_end_addr = riscv_load_firmware(firmware_filename,
                                                firmware_load_addr, sym_cb);
        g_free(firmware_filename);
    }

    return firmware_end_addr;
}

char *riscv_find_firmware(const char *firmware_filename)
{
    char *filename;

    filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, firmware_filename);
    if (filename == NULL) {
        if (!qtest_enabled()) {
            /*
             * We only ship plain binary bios images in the QEMU source.
             * With Spike machine that uses ELF images as the default bios,
             * running QEMU test will complain hence let's suppress the error
             * report for QEMU testing.
             */
            error_report("Unable to load the RISC-V firmware \"%s\"",
                         firmware_filename);
            exit(1);
        }
    }

    return filename;
}

target_ulong riscv_load_firmware(const char *firmware_filename,
                                 hwaddr firmware_load_addr,
                                 symbol_fn_t sym_cb)
{
    uint64_t firmware_entry, firmware_end;
    ssize_t firmware_size;

    if (load_elf_ram_sym(firmware_filename, NULL, NULL, NULL,
                         &firmware_entry, NULL, &firmware_end, NULL,
                         0, EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
        return firmware_end;
    }

    firmware_size = load_image_targphys_as(firmware_filename,
                                           firmware_load_addr,
                                           current_machine->ram_size, NULL);

    if (firmware_size > 0) {
        return firmware_load_addr + firmware_size;
    }

    error_report("could not load firmware '%s'", firmware_filename);
    exit(1);
}

target_ulong riscv_load_kernel(const char *kernel_filename,
                               target_ulong kernel_start_addr,
                               symbol_fn_t sym_cb)
{
    uint64_t kernel_load_base, kernel_entry;

    /*
     * NB: Use low address not ELF entry point to ensure that the fw_dynamic
     * behaviour when loading an ELF matches the fw_payload, fw_jump and BBL
     * behaviour, as well as fw_dynamic with a raw binary, all of which jump to
     * the (expected) load address load address. This allows kernels to have
     * separate SBI and ELF entry points (used by FreeBSD, for example).
     */
    if (load_elf_ram_sym(kernel_filename, NULL, NULL, NULL,
                         NULL, &kernel_load_base, NULL, NULL, 0,
                         EM_RISCV, 1, 0, NULL, true, sym_cb) > 0) {
        return kernel_load_base;
    }

    if (load_uimage_as(kernel_filename, &kernel_entry, NULL, NULL,
                       NULL, NULL, NULL) > 0) {
        return kernel_entry;
    }

    if (load_image_targphys_as(kernel_filename, kernel_start_addr,
                               current_machine->ram_size, NULL) > 0) {
        return kernel_start_addr;
    }

    error_report("could not load kernel '%s'", kernel_filename);
    exit(1);
}

hwaddr riscv_load_initrd(const char *filename, uint64_t mem_size,
                         uint64_t kernel_entry, hwaddr *start)
{
    ssize_t size;

    /*
     * We want to put the initrd far enough into RAM that when the
     * kernel is uncompressed it will not clobber the initrd. However
     * on boards without much RAM we must ensure that we still leave
     * enough room for a decent sized initrd, and on boards with large
     * amounts of RAM we must avoid the initrd being so far up in RAM
     * that it is outside lowmem and inaccessible to the kernel.
     * So for boards with less  than 256MB of RAM we put the initrd
     * halfway into RAM, and for boards with 256MB of RAM or more we put
     * the initrd at 128MB.
     */
    *start = kernel_entry + MIN(mem_size / 2, 128 * MiB);

    size = load_ramdisk(filename, *start, mem_size - *start);
    if (size == -1) {
        size = load_image_targphys(filename, *start, mem_size - *start);
        if (size == -1) {
            error_report("could not load ramdisk '%s'", filename);
            exit(1);
        }
    }

    return *start + size;
}

uint64_t riscv_load_fdt(hwaddr dram_base, uint64_t mem_size, void *fdt)
{
    uint64_t temp, fdt_addr;
    hwaddr dram_end = dram_base + mem_size;
    int ret, fdtsize = fdt_totalsize(fdt);

    if (fdtsize <= 0) {
        error_report("invalid device-tree");
        exit(1);
    }

    /*
     * We should put fdt as far as possible to avoid kernel/initrd overwriting
     * its content. But it should be addressable by 32 bit system as well.
     * Thus, put it at an 2MB aligned address that less than fdt size from the
     * end of dram or 3GB whichever is lesser.
     */
    temp = (dram_base < 3072 * MiB) ? MIN(dram_end, 3072 * MiB) : dram_end;
    fdt_addr = QEMU_ALIGN_DOWN(temp - fdtsize, 2 * MiB);

    ret = fdt_pack(fdt);
    /* Should only fail if we've built a corrupted tree */
    g_assert(ret == 0);
    /* copy in the device tree */
    qemu_fdt_dumpdtb(fdt, fdtsize);

    rom_add_blob_fixed_as("fdt", fdt, fdtsize, fdt_addr,
                          &address_space_memory);

    return fdt_addr;
}

void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
                                  hwaddr rom_size, uint32_t reset_vec_size,
                                  uint64_t kernel_entry)
{
    struct fw_dynamic_info dinfo;
    size_t dinfo_len;

    if (sizeof(dinfo.magic) == 4) {
        dinfo.magic = cpu_to_le32(FW_DYNAMIC_INFO_MAGIC_VALUE);
        dinfo.version = cpu_to_le32(FW_DYNAMIC_INFO_VERSION);
        dinfo.next_mode = cpu_to_le32(FW_DYNAMIC_INFO_NEXT_MODE_S);
        dinfo.next_addr = cpu_to_le32(kernel_entry);
    } else {
        dinfo.magic = cpu_to_le64(FW_DYNAMIC_INFO_MAGIC_VALUE);
        dinfo.version = cpu_to_le64(FW_DYNAMIC_INFO_VERSION);
        dinfo.next_mode = cpu_to_le64(FW_DYNAMIC_INFO_NEXT_MODE_S);
        dinfo.next_addr = cpu_to_le64(kernel_entry);
    }
    dinfo.options = 0;
    dinfo.boot_hart = 0;
    dinfo_len = sizeof(dinfo);

    /**
     * copy the dynamic firmware info. This information is specific to
     * OpenSBI but doesn't break any other firmware as long as they don't
     * expect any certain value in "a2" register.
     */
    if (dinfo_len > (rom_size - reset_vec_size)) {
        error_report("not enough space to store dynamic firmware info");
        exit(1);
    }

    rom_add_blob_fixed_as("mrom.finfo", &dinfo, dinfo_len,
                           rom_base + reset_vec_size,
                           &address_space_memory);
}

void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts,
                               hwaddr start_addr,
                               hwaddr rom_base, hwaddr rom_size,
                               uint64_t kernel_entry,
                               uint64_t fdt_load_addr)
{
    int i;
    uint32_t start_addr_hi32 = 0x00000000;
    uint32_t fdt_load_addr_hi32 = 0x00000000;

    if (!riscv_is_32bit(harts)) {
        start_addr_hi32 = start_addr >> 32;
        fdt_load_addr_hi32 = fdt_load_addr >> 32;
    }
    /* reset vector */
    uint32_t reset_vec[10] = {
        0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(fw_dyn) */
        0x02828613,                  /*     addi   a2, t0, %pcrel_lo(1b) */
        0xf1402573,                  /*     csrr   a0, mhartid  */
        0,
        0,
        0x00028067,                  /*     jr     t0 */
        start_addr,                  /* start: .dword */
        start_addr_hi32,
        fdt_load_addr,               /* fdt_laddr: .dword */
        fdt_load_addr_hi32,
                                     /* fw_dyn: */
    };
    if (riscv_is_32bit(harts)) {
        reset_vec[3] = 0x0202a583;   /*     lw     a1, 32(t0) */
        reset_vec[4] = 0x0182a283;   /*     lw     t0, 24(t0) */
    } else {
        reset_vec[3] = 0x0202b583;   /*     ld     a1, 32(t0) */
        reset_vec[4] = 0x0182b283;   /*     ld     t0, 24(t0) */
    }

    /* copy in the reset vector in little_endian byte order */
    for (i = 0; i < ARRAY_SIZE(reset_vec); i++) {
        reset_vec[i] = cpu_to_le32(reset_vec[i]);
    }
    rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
                          rom_base, &address_space_memory);
    riscv_rom_copy_firmware_info(machine, rom_base, rom_size, sizeof(reset_vec),
                                 kernel_entry);
}

void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
{
    CPUState *cs;

    for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
        RISCVCPU *riscv_cpu = RISCV_CPU(cs);
        riscv_cpu->env.kernel_addr = kernel_addr;
        riscv_cpu->env.fdt_addr = fdt_addr;
    }
}