diff options
Diffstat (limited to 'src/arm/linux/chipset.c')
| -rw-r--r-- | src/arm/linux/chipset.c | 117 |
1 files changed, 116 insertions, 1 deletions
diff --git a/src/arm/linux/chipset.c b/src/arm/linux/chipset.c index 35058d9..e36283c 100644 --- a/src/arm/linux/chipset.c +++ b/src/arm/linux/chipset.c @@ -1012,11 +1012,58 @@ write_chipset: } /** + * Tries to match /BCM\d{4}$/ signature for Broadcom BCM chipsets. + * If match successful, extracts model information into \p chipset argument. + * + * @param start - start of the /proc/cpuinfo Hardware string to match. + * @param end - end of the /proc/cpuinfo Hardware string to match. + * @param[out] chipset - location where chipset information will be stored upon a successful match. + * + * @returns true if signature matched, false otherwise. + */ +static bool match_bcm( + const char* start, const char* end, + struct cpuinfo_arm_chipset chipset[restrict static 1]) +{ + /* Expect exactly 7 symbols: "BCM" (3 symbols) + 4-digit model number */ + if (start + 7 != end) { + return false; + } + + /* Check that the string starts with "BCM". + * The first three characters are loaded and compared as a 24-bit little endian word. + */ + const uint32_t expected_bcm = load_u24le(start); + if (expected_bcm != UINT32_C(0x004D4342) /* "MCB" = reverse("BCM") */) { + return false; + } + + /* Validate and parse 4-digit model number */ + uint32_t model = 0; + for (uint32_t i = 3; i < 7; i++) { + const uint32_t digit = (uint32_t) (uint8_t) start[i] - '0'; + if (digit >= 10) { + /* Not really a digit */ + return false; + } + model = model * 10 + digit; + } + + /* Return parsed chipset. */ + *chipset = (struct cpuinfo_arm_chipset) { + .vendor = cpuinfo_arm_chipset_vendor_broadcom, + .series = cpuinfo_arm_chipset_series_broadcom_bcm, + .model = model, + }; + return true; +} + +/** * Tries to match /OMAP\d{4}$/ signature for Texas Instruments OMAP chipsets. * If match successful, extracts model information into \p chipset argument. * * @param start - start of the /proc/cpuinfo Hardware string to match. - * @param end - end of the /proc/cpuinfo Hardaware string to match. + * @param end - end of the /proc/cpuinfo Hardware string to match. * @param[out] chipset - location where chipset information will be stored upon a successful match. * * @returns true if signature matched, false otherwise. @@ -2328,6 +2375,14 @@ struct cpuinfo_arm_chipset cpuinfo_arm_linux_decode_chipset_from_proc_cpuinfo_ha return chipset; } + /* Check Broadcom BCM signature */ + if (match_bcm(hardware, hardware_end, &chipset)) { + cpuinfo_log_debug( + "matched Broadcom BCM signature in /proc/cpuinfo Hardware string \"%.*s\"", + (int) hardware_length, hardware); + return chipset; + } + #if CPUINFO_ARCH_ARM /* Check Texas Instruments OMAP signature */ if (match_omap(hardware, hardware_end, &chipset)) { @@ -3713,6 +3768,62 @@ void cpuinfo_arm_chipset_to_string( return chipset; } #else /* !defined(__ANDROID__) */ + /* + * Fix commonly misreported Broadcom BCM models on Raspberry Pi boards. + * + * @param[in,out] chipset - chipset name to fix. + * @param[in] revision - /proc/cpuinfo Revision string. + */ + void cpuinfo_arm_fixup_raspberry_pi_chipset( + struct cpuinfo_arm_chipset chipset[restrict static 1], + const char revision[restrict static CPUINFO_HARDWARE_VALUE_MAX]) + { + const size_t revision_length = strnlen(revision, CPUINFO_REVISION_VALUE_MAX); + + /* Parse revision codes according to https://www.raspberrypi.org/documentation/hardware/raspberrypi/revision-codes/README.md */ + #if CPUINFO_ARCH_ARM + if (revision_length == 4) { + /* + * Old-style revision codes. + * All Raspberry Pi models with old-style revision code use Broadcom BCM2835. + */ + + /* BCM2835 often misreported as BCM2708 */ + if (chipset->model == 2708) { + chipset->model = 2835; + } + return; + } + #endif + if ((size_t) (revision_length - 5) <= (size_t) (8 - 5) /* 5 <= length(revision) <= 8 */) { + /* New-style revision codes */ + + uint32_t model = 0; + switch (revision[revision_length - 4]) { + case '0': + /* BCM2835 */ + model = 2835; + break; + case '1': + /* BCM2836 */ + model = 2836; + break; + case '2': + /* BCM2837 */ + model = 2837; + break; + case '3': + /* BCM2711 */ + model = 2711; + break; + } + + if (model != 0) { + chipset->model = model; + chipset->suffix[0] = 0; + } + } + } /* * Decodes chipset name from /proc/cpuinfo Hardware string. @@ -3727,6 +3838,7 @@ void cpuinfo_arm_chipset_to_string( */ struct cpuinfo_arm_chipset cpuinfo_arm_linux_decode_chipset( const char hardware[restrict static CPUINFO_HARDWARE_VALUE_MAX], + const char revision[restrict static CPUINFO_REVISION_VALUE_MAX], uint32_t cores, uint32_t max_cpu_freq_max) { @@ -3736,6 +3848,9 @@ void cpuinfo_arm_chipset_to_string( if (chipset.vendor == cpuinfo_arm_chipset_vendor_unknown) { cpuinfo_log_warning( "chipset detection failed: /proc/cpuinfo Hardware string did not match known signatures"); + } else if (chipset.vendor == cpuinfo_arm_chipset_vendor_broadcom) { + /* Raspberry Pi kernel reports bogus chipset models; detect chipset from RPi revision */ + cpuinfo_arm_fixup_raspberry_pi_chipset(&chipset, revision); } else { cpuinfo_arm_fixup_chipset(&chipset, cores, max_cpu_freq_max); } |