diff options
Diffstat (limited to 'arch/arm/cpu/armv8/sec_firmware.c')
| -rw-r--r-- | arch/arm/cpu/armv8/sec_firmware.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv8/sec_firmware.c b/arch/arm/cpu/armv8/sec_firmware.c index fffce71..0e74834 100644 --- a/arch/arm/cpu/armv8/sec_firmware.c +++ b/arch/arm/cpu/armv8/sec_firmware.c @@ -232,6 +232,59 @@ unsigned int sec_firmware_support_psci_version(void) #endif /* + * Check with sec_firmware if it supports random number generation + * via HW RNG + * + * The return value will be true if it is supported + */ +bool sec_firmware_support_hwrng(void) +{ + uint8_t rand[8]; + if (sec_firmware_addr & SEC_FIRMWARE_RUNNING) { + if (!sec_firmware_get_random(rand, 8)) + return true; + } + + return false; +} + +/* + * sec_firmware_get_random - Get a random number from SEC Firmware + * @rand: random number buffer to be filled + * @bytes: Number of bytes of random number to be supported + * @eret: -1 in case of error, 0 for success + */ +int sec_firmware_get_random(uint8_t *rand, int bytes) +{ + unsigned long long num; + struct pt_regs regs; + int param1; + + if (!bytes || bytes > 8) { + printf("Max Random bytes genration supported is 8\n"); + return -1; + } +#define SIP_RNG_64 0xC200FF11 + regs.regs[0] = SIP_RNG_64; + + if (bytes <= 4) + param1 = 0; + else + param1 = 1; + regs.regs[1] = param1; + + smc_call(®s); + + if (regs.regs[0]) + return -1; + + num = regs.regs[1]; + memcpy(rand, &num, bytes); + + return 0; +} + +/* * sec_firmware_init - Initialize the SEC Firmware * @sec_firmware_img: the SEC Firmware image address * @eret_hold_l: the address to hold exception return address low @@ -278,3 +331,49 @@ int sec_firmware_init(const void *sec_firmware_img, return 0; } + +/* + * fdt_fix_kaslr - Add kalsr-seed node in Device tree + * @fdt: Device tree + * @eret: 0 in case of error, 1 for success + */ +int fdt_fixup_kaslr(void *fdt) +{ + int nodeoffset; + int err, ret = 0; + u8 rand[8]; + +#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT) + /* Check if random seed generation is supported */ + if (sec_firmware_support_hwrng() == false) + return 0; + + ret = sec_firmware_get_random(rand, 8); + if (ret < 0) { + printf("WARNING: No random number to set kaslr-seed\n"); + return 0; + } + + err = fdt_check_header(fdt); + if (err < 0) { + printf("fdt_chosen: %s\n", fdt_strerror(err)); + return 0; + } + + /* find or create "/chosen" node. */ + nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen"); + if (nodeoffset < 0) + return 0; + + err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand, + sizeof(rand)); + if (err < 0) { + printf("WARNING: can't set kaslr-seed %s.\n", + fdt_strerror(err)); + return 0; + } + ret = 1; +#endif + + return ret; +} |