diff --git a/docs/system/arm/nuvoton.rst b/docs/system/arm/nuvoton.rst index e3e1a3a3a7..4342434df4 100644 --- a/docs/system/arm/nuvoton.rst +++ b/docs/system/arm/nuvoton.rst @@ -38,6 +38,7 @@ Supported devices * DDR4 memory controller (dummy interface indicating memory training is done) * OTP controllers (no protection features) * Flash Interface Unit (FIU; no protection features) + * Random Number Generator (RNG) Missing devices --------------- @@ -59,7 +60,6 @@ Missing devices * Peripheral SPI controller (PSPI) * Analog to Digital Converter (ADC) * SD/MMC host - * Random Number Generator (RNG) * PECI interface * Pulse Width Modulation (PWM) * Tachometer diff --git a/hw/arm/npcm7xx.c b/hw/arm/npcm7xx.c index c341dcab8b..cb4db41c54 100644 --- a/hw/arm/npcm7xx.c +++ b/hw/arm/npcm7xx.c @@ -44,6 +44,7 @@ #define NPCM7XX_GCR_BA (0xf0800000) #define NPCM7XX_CLK_BA (0xf0801000) #define NPCM7XX_MC_BA (0xf0824000) +#define NPCM7XX_RNG_BA (0xf000b000) /* Internal AHB SRAM */ #define NPCM7XX_RAM3_BA (0xc0008000) @@ -256,6 +257,7 @@ static void npcm7xx_init(Object *obj) object_initialize_child(obj, "otp2", &s->fuse_array, TYPE_NPCM7XX_FUSE_ARRAY); object_initialize_child(obj, "mc", &s->mc, TYPE_NPCM7XX_MC); + object_initialize_child(obj, "rng", &s->rng, TYPE_NPCM7XX_RNG); for (i = 0; i < ARRAY_SIZE(s->tim); i++) { object_initialize_child(obj, "tim[*]", &s->tim[i], TYPE_NPCM7XX_TIMER); @@ -374,6 +376,10 @@ static void npcm7xx_realize(DeviceState *dev, Error **errp) serial_hd(i), DEVICE_LITTLE_ENDIAN); } + /* Random Number Generator. Cannot fail. */ + sysbus_realize(SYS_BUS_DEVICE(&s->rng), &error_abort); + sysbus_mmio_map(SYS_BUS_DEVICE(&s->rng), 0, NPCM7XX_RNG_BA); + /* * Flash Interface Unit (FIU). Can fail if incorrect number of chip selects * specified, but this is a programming error. @@ -412,7 +418,6 @@ static void npcm7xx_realize(DeviceState *dev, Error **errp) create_unimplemented_device("npcm7xx.vdmx", 0xe0800000, 4 * KiB); create_unimplemented_device("npcm7xx.pcierc", 0xe1000000, 64 * KiB); create_unimplemented_device("npcm7xx.kcs", 0xf0007000, 4 * KiB); - create_unimplemented_device("npcm7xx.rng", 0xf000b000, 4 * KiB); create_unimplemented_device("npcm7xx.adc", 0xf000c000, 4 * KiB); create_unimplemented_device("npcm7xx.gfxi", 0xf000e000, 4 * KiB); create_unimplemented_device("npcm7xx.gpio[0]", 0xf0010000, 4 * KiB); diff --git a/hw/misc/meson.build b/hw/misc/meson.build index 793d45b1dc..7ffb44b587 100644 --- a/hw/misc/meson.build +++ b/hw/misc/meson.build @@ -59,6 +59,7 @@ softmmu_ss.add(when: 'CONFIG_MAINSTONE', if_true: files('mst_fpga.c')) softmmu_ss.add(when: 'CONFIG_NPCM7XX', if_true: files( 'npcm7xx_clk.c', 'npcm7xx_gcr.c', + 'npcm7xx_rng.c', )) softmmu_ss.add(when: 'CONFIG_OMAP', if_true: files( 'omap_clk.c', diff --git a/hw/misc/npcm7xx_rng.c b/hw/misc/npcm7xx_rng.c new file mode 100644 index 0000000000..f650f3401f --- /dev/null +++ b/hw/misc/npcm7xx_rng.c @@ -0,0 +1,180 @@ +/* + * Nuvoton NPCM7xx Random Number Generator. + * + * Copyright 2020 Google LLC + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + */ + +#include "qemu/osdep.h" + +#include "hw/misc/npcm7xx_rng.h" +#include "migration/vmstate.h" +#include "qemu/bitops.h" +#include "qemu/guest-random.h" +#include "qemu/log.h" +#include "qemu/module.h" +#include "qemu/units.h" + +#include "trace.h" + +#define NPCM7XX_RNG_REGS_SIZE (4 * KiB) + +#define NPCM7XX_RNGCS (0x00) +#define NPCM7XX_RNGCS_CLKP(rv) extract32(rv, 2, 4) +#define NPCM7XX_RNGCS_DVALID BIT(1) +#define NPCM7XX_RNGCS_RNGE BIT(0) + +#define NPCM7XX_RNGD (0x04) +#define NPCM7XX_RNGMODE (0x08) +#define NPCM7XX_RNGMODE_NORMAL (0x02) + +static bool npcm7xx_rng_is_enabled(NPCM7xxRNGState *s) +{ + return (s->rngcs & NPCM7XX_RNGCS_RNGE) && + (s->rngmode == NPCM7XX_RNGMODE_NORMAL); +} + +static uint64_t npcm7xx_rng_read(void *opaque, hwaddr offset, unsigned size) +{ + NPCM7xxRNGState *s = opaque; + uint64_t value = 0; + + switch (offset) { + case NPCM7XX_RNGCS: + /* + * If the RNG is enabled, but we don't have any valid random data, try + * obtaining some and update the DVALID bit accordingly. + */ + if (!npcm7xx_rng_is_enabled(s)) { + s->rngcs &= ~NPCM7XX_RNGCS_DVALID; + } else if (!(s->rngcs & NPCM7XX_RNGCS_DVALID)) { + uint8_t byte = 0; + + if (qemu_guest_getrandom(&byte, sizeof(byte), NULL) == 0) { + s->rngd = byte; + s->rngcs |= NPCM7XX_RNGCS_DVALID; + } + } + value = s->rngcs; + break; + case NPCM7XX_RNGD: + if (npcm7xx_rng_is_enabled(s) && s->rngcs & NPCM7XX_RNGCS_DVALID) { + s->rngcs &= ~NPCM7XX_RNGCS_DVALID; + value = s->rngd; + s->rngd = 0; + } + break; + case NPCM7XX_RNGMODE: + value = s->rngmode; + break; + + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: read from invalid offset 0x%" HWADDR_PRIx "\n", + DEVICE(s)->canonical_path, offset); + break; + } + + trace_npcm7xx_rng_read(offset, value, size); + + return value; +} + +static void npcm7xx_rng_write(void *opaque, hwaddr offset, uint64_t value, + unsigned size) +{ + NPCM7xxRNGState *s = opaque; + + trace_npcm7xx_rng_write(offset, value, size); + + switch (offset) { + case NPCM7XX_RNGCS: + s->rngcs &= NPCM7XX_RNGCS_DVALID; + s->rngcs |= value & ~NPCM7XX_RNGCS_DVALID; + break; + case NPCM7XX_RNGD: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: write to read-only register @ 0x%" HWADDR_PRIx "\n", + DEVICE(s)->canonical_path, offset); + break; + case NPCM7XX_RNGMODE: + s->rngmode = value; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: write to invalid offset 0x%" HWADDR_PRIx "\n", + DEVICE(s)->canonical_path, offset); + break; + } +} + +static const MemoryRegionOps npcm7xx_rng_ops = { + .read = npcm7xx_rng_read, + .write = npcm7xx_rng_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid = { + .min_access_size = 1, + .max_access_size = 4, + .unaligned = false, + }, +}; + +static void npcm7xx_rng_enter_reset(Object *obj, ResetType type) +{ + NPCM7xxRNGState *s = NPCM7XX_RNG(obj); + + s->rngcs = 0; + s->rngd = 0; + s->rngmode = 0; +} + +static void npcm7xx_rng_init(Object *obj) +{ + NPCM7xxRNGState *s = NPCM7XX_RNG(obj); + + memory_region_init_io(&s->iomem, obj, &npcm7xx_rng_ops, s, "regs", + NPCM7XX_RNG_REGS_SIZE); + sysbus_init_mmio(&s->parent, &s->iomem); +} + +static const VMStateDescription vmstate_npcm7xx_rng = { + .name = "npcm7xx-rng", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_UINT8(rngcs, NPCM7xxRNGState), + VMSTATE_UINT8(rngd, NPCM7xxRNGState), + VMSTATE_UINT8(rngmode, NPCM7xxRNGState), + VMSTATE_END_OF_LIST(), + }, +}; + +static void npcm7xx_rng_class_init(ObjectClass *klass, void *data) +{ + ResettableClass *rc = RESETTABLE_CLASS(klass); + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->desc = "NPCM7xx Random Number Generator"; + dc->vmsd = &vmstate_npcm7xx_rng; + rc->phases.enter = npcm7xx_rng_enter_reset; +} + +static const TypeInfo npcm7xx_rng_types[] = { + { + .name = TYPE_NPCM7XX_RNG, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(NPCM7xxRNGState), + .class_init = npcm7xx_rng_class_init, + .instance_init = npcm7xx_rng_init, + }, +}; +DEFINE_TYPES(npcm7xx_rng_types); diff --git a/hw/misc/trace-events b/hw/misc/trace-events index 6054f9adf3..b2f060ad77 100644 --- a/hw/misc/trace-events +++ b/hw/misc/trace-events @@ -118,6 +118,10 @@ npcm7xx_clk_write(uint64_t offset, uint32_t value) "offset: 0x%04" PRIx64 " valu npcm7xx_gcr_read(uint64_t offset, uint32_t value) " offset: 0x%04" PRIx64 " value: 0x%08" PRIx32 npcm7xx_gcr_write(uint64_t offset, uint32_t value) "offset: 0x%04" PRIx64 " value: 0x%08" PRIx32 +# npcm7xx_rng.c +npcm7xx_rng_read(uint64_t offset, uint64_t value, unsigned size) "offset: 0x%04" PRIx64 " value: 0x%02" PRIx64 " size: %u" +npcm7xx_rng_write(uint64_t offset, uint64_t value, unsigned size) "offset: 0x%04" PRIx64 " value: 0x%02" PRIx64 " size: %u" + # stm32f4xx_syscfg.c stm32f4xx_syscfg_set_irq(int gpio, int line, int level) "Interupt: GPIO: %d, Line: %d; Level: %d" stm32f4xx_pulse_exti(int irq) "Pulse EXTI: %d" diff --git a/include/hw/arm/npcm7xx.h b/include/hw/arm/npcm7xx.h index 13106af215..761f9b987e 100644 --- a/include/hw/arm/npcm7xx.h +++ b/include/hw/arm/npcm7xx.h @@ -21,6 +21,7 @@ #include "hw/mem/npcm7xx_mc.h" #include "hw/misc/npcm7xx_clk.h" #include "hw/misc/npcm7xx_gcr.h" +#include "hw/misc/npcm7xx_rng.h" #include "hw/nvram/npcm7xx_otp.h" #include "hw/timer/npcm7xx_timer.h" #include "hw/ssi/npcm7xx_fiu.h" @@ -75,6 +76,7 @@ typedef struct NPCM7xxState { NPCM7xxOTPState key_storage; NPCM7xxOTPState fuse_array; NPCM7xxMCState mc; + NPCM7xxRNGState rng; NPCM7xxFIUState fiu[2]; } NPCM7xxState; diff --git a/include/hw/misc/npcm7xx_rng.h b/include/hw/misc/npcm7xx_rng.h new file mode 100644 index 0000000000..5e85fd439d --- /dev/null +++ b/include/hw/misc/npcm7xx_rng.h @@ -0,0 +1,34 @@ +/* + * Nuvoton NPCM7xx Random Number Generator. + * + * Copyright 2020 Google LLC + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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 NPCM7XX_RNG_H +#define NPCM7XX_RNG_H + +#include "hw/sysbus.h" + +typedef struct NPCM7xxRNGState { + SysBusDevice parent; + + MemoryRegion iomem; + + uint8_t rngcs; + uint8_t rngd; + uint8_t rngmode; +} NPCM7xxRNGState; + +#define TYPE_NPCM7XX_RNG "npcm7xx-rng" +#define NPCM7XX_RNG(obj) OBJECT_CHECK(NPCM7xxRNGState, (obj), TYPE_NPCM7XX_RNG) + +#endif /* NPCM7XX_RNG_H */ diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build index 6c9d3426d1..43e71a3d5b 100644 --- a/tests/qtest/meson.build +++ b/tests/qtest/meson.build @@ -133,7 +133,10 @@ qtests_sparc64 = \ (config_all_devices.has_key('CONFIG_ISA_TESTDEV') ? ['endianness-test'] : []) + \ ['prom-env-test', 'boot-serial-test'] -qtests_npcm7xx = ['npcm7xx_timer-test', 'npcm7xx_watchdog_timer-test'] +qtests_npcm7xx = \ + ['npcm7xx_rng-test', + 'npcm7xx_timer-test', + 'npcm7xx_watchdog_timer-test'] qtests_arm = \ (config_all_devices.has_key('CONFIG_PFLASH_CFI02') ? ['pflash-cfi02-test'] : []) + \ (config_all_devices.has_key('CONFIG_NPCM7XX') ? qtests_npcm7xx : []) + \ diff --git a/tests/qtest/npcm7xx_rng-test.c b/tests/qtest/npcm7xx_rng-test.c new file mode 100644 index 0000000000..da6e639bf6 --- /dev/null +++ b/tests/qtest/npcm7xx_rng-test.c @@ -0,0 +1,278 @@ +/* + * QTest testcase for the Nuvoton NPCM7xx Random Number Generator + * + * Copyright 2020 Google LLC + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + */ + +#include "qemu/osdep.h" + +#include + +#include "libqtest-single.h" +#include "qemu/bitops.h" + +#define RNG_BASE_ADDR 0xf000b000 + +/* Control and Status Register */ +#define RNGCS 0x00 +# define DVALID BIT(1) /* Data Valid */ +# define RNGE BIT(0) /* RNG Enable */ +/* Data Register */ +#define RNGD 0x04 +/* Mode Register */ +#define RNGMODE 0x08 +# define ROSEL_NORMAL (2) /* RNG only works in this mode */ + +/* Number of bits to collect for randomness tests. */ +#define TEST_INPUT_BITS (128) + +static void rng_writeb(unsigned int offset, uint8_t value) +{ + writeb(RNG_BASE_ADDR + offset, value); +} + +static uint8_t rng_readb(unsigned int offset) +{ + return readb(RNG_BASE_ADDR + offset); +} + +/* Disable RNG and set normal ring oscillator mode. */ +static void rng_reset(void) +{ + rng_writeb(RNGCS, 0); + rng_writeb(RNGMODE, ROSEL_NORMAL); +} + +/* Reset RNG and then enable it. */ +static void rng_reset_enable(void) +{ + rng_reset(); + rng_writeb(RNGCS, RNGE); +} + +/* Wait until Data Valid bit is set. */ +static bool rng_wait_ready(void) +{ + /* qemu_guest_getrandom may fail. Assume it won't fail 10 times in a row. */ + int retries = 10; + + while (retries-- > 0) { + if (rng_readb(RNGCS) & DVALID) { + return true; + } + } + + return false; +} + +/* + * Perform a frequency (monobit) test, as defined by NIST SP 800-22, on the + * sequence in buf and return the P-value. This represents the probability of a + * truly random sequence having the same proportion of zeros and ones as the + * sequence in buf. + * + * An RNG which always returns 0x00 or 0xff, or has some bits stuck at 0 or 1, + * will fail this test. However, an RNG which always returns 0x55, 0xf0 or some + * other value with an equal number of zeroes and ones will pass. + */ +static double calc_monobit_p(const uint8_t *buf, unsigned int len) +{ + unsigned int i; + double s_obs; + int sn = 0; + + for (i = 0; i < len; i++) { + /* + * Each 1 counts as 1, each 0 counts as -1. + * s = cp - (8 - cp) = 2 * cp - 8 + */ + sn += 2 * ctpop8(buf[i]) - 8; + } + + s_obs = abs(sn) / sqrt(len * BITS_PER_BYTE); + + return erfc(s_obs / sqrt(2)); +} + +/* + * Perform a runs test, as defined by NIST SP 800-22, and return the P-value. + * This represents the probability of a truly random sequence having the same + * number of runs (i.e. uninterrupted sequences of identical bits) as the + * sequence in buf. + */ +static double calc_runs_p(const unsigned long *buf, unsigned int nr_bits) +{ + unsigned int j; + unsigned int k; + int nr_ones = 0; + int vn_obs = 0; + double pi; + + g_assert(nr_bits % BITS_PER_LONG == 0); + + for (j = 0; j < nr_bits / BITS_PER_LONG; j++) { + nr_ones += __builtin_popcountl(buf[j]); + } + pi = (double)nr_ones / nr_bits; + + for (k = 0; k < nr_bits - 1; k++) { + vn_obs += !(test_bit(k, buf) ^ test_bit(k + 1, buf)); + } + vn_obs += 1; + + return erfc(fabs(vn_obs - 2 * nr_bits * pi * (1.0 - pi)) + / (2 * sqrt(2 * nr_bits) * pi * (1.0 - pi))); +} + +/* + * Verifies that DVALID is clear, and RNGD reads zero, when RNGE is cleared, + * and DVALID eventually becomes set when RNGE is set. + */ +static void test_enable_disable(void) +{ + /* Disable: DVALID should not be set, and RNGD should read zero */ + rng_reset(); + g_assert_cmphex(rng_readb(RNGCS), ==, 0); + g_assert_cmphex(rng_readb(RNGD), ==, 0); + + /* Enable: DVALID should be set, but we can't make assumptions about RNGD */ + rng_writeb(RNGCS, RNGE); + g_assert_true(rng_wait_ready()); + g_assert_cmphex(rng_readb(RNGCS), ==, DVALID | RNGE); + + /* Disable: DVALID should not be set, and RNGD should read zero */ + rng_writeb(RNGCS, 0); + g_assert_cmphex(rng_readb(RNGCS), ==, 0); + g_assert_cmphex(rng_readb(RNGD), ==, 0); +} + +/* + * Verifies that the RNG only produces data when RNGMODE is set to 'normal' + * ring oscillator mode. + */ +static void test_rosel(void) +{ + rng_reset_enable(); + g_assert_true(rng_wait_ready()); + rng_writeb(RNGMODE, 0); + g_assert_false(rng_wait_ready()); + rng_writeb(RNGMODE, ROSEL_NORMAL); + g_assert_true(rng_wait_ready()); + rng_writeb(RNGMODE, 0); + g_assert_false(rng_wait_ready()); +} + +/* + * Verifies that a continuous sequence of bits collected after enabling the RNG + * satisfies a monobit test. + */ +static void test_continuous_monobit(void) +{ + uint8_t buf[TEST_INPUT_BITS / BITS_PER_BYTE]; + unsigned int i; + + rng_reset_enable(); + for (i = 0; i < sizeof(buf); i++) { + g_assert_true(rng_wait_ready()); + buf[i] = rng_readb(RNGD); + } + + g_assert_cmpfloat(calc_monobit_p(buf, sizeof(buf)), >, 0.01); +} + +/* + * Verifies that a continuous sequence of bits collected after enabling the RNG + * satisfies a runs test. + */ +static void test_continuous_runs(void) +{ + union { + unsigned long l[TEST_INPUT_BITS / BITS_PER_LONG]; + uint8_t c[TEST_INPUT_BITS / BITS_PER_BYTE]; + } buf; + unsigned int i; + + rng_reset_enable(); + for (i = 0; i < sizeof(buf); i++) { + g_assert_true(rng_wait_ready()); + buf.c[i] = rng_readb(RNGD); + } + + g_assert_cmpfloat(calc_runs_p(buf.l, sizeof(buf) * BITS_PER_BYTE), >, 0.01); +} + +/* + * Verifies that the first data byte collected after enabling the RNG satisfies + * a monobit test. + */ +static void test_first_byte_monobit(void) +{ + /* Enable, collect one byte, disable. Repeat until we have 100 bits. */ + uint8_t buf[TEST_INPUT_BITS / BITS_PER_BYTE]; + unsigned int i; + + rng_reset(); + for (i = 0; i < sizeof(buf); i++) { + rng_writeb(RNGCS, RNGE); + g_assert_true(rng_wait_ready()); + buf[i] = rng_readb(RNGD); + rng_writeb(RNGCS, 0); + } + + g_assert_cmpfloat(calc_monobit_p(buf, sizeof(buf)), >, 0.01); +} + +/* + * Verifies that the first data byte collected after enabling the RNG satisfies + * a runs test. + */ +static void test_first_byte_runs(void) +{ + /* Enable, collect one byte, disable. Repeat until we have 100 bits. */ + union { + unsigned long l[TEST_INPUT_BITS / BITS_PER_LONG]; + uint8_t c[TEST_INPUT_BITS / BITS_PER_BYTE]; + } buf; + unsigned int i; + + rng_reset(); + for (i = 0; i < sizeof(buf); i++) { + rng_writeb(RNGCS, RNGE); + g_assert_true(rng_wait_ready()); + buf.c[i] = rng_readb(RNGD); + rng_writeb(RNGCS, 0); + } + + g_assert_cmpfloat(calc_runs_p(buf.l, sizeof(buf) * BITS_PER_BYTE), >, 0.01); +} + +int main(int argc, char **argv) +{ + int ret; + + g_test_init(&argc, &argv, NULL); + g_test_set_nonfatal_assertions(); + + qtest_add_func("npcm7xx_rng/enable_disable", test_enable_disable); + qtest_add_func("npcm7xx_rng/rosel", test_rosel); + qtest_add_func("npcm7xx_rng/continuous/monobit", test_continuous_monobit); + qtest_add_func("npcm7xx_rng/continuous/runs", test_continuous_runs); + qtest_add_func("npcm7xx_rng/first_byte/monobit", test_first_byte_monobit); + qtest_add_func("npcm7xx_rng/first_byte/runs", test_first_byte_runs); + + qtest_start("-machine npcm750-evb"); + ret = g_test_run(); + qtest_end(); + + return ret; +}