diff options
| -rw-r--r-- | host/lib/crossystem.c | 54 | ||||
| -rw-r--r-- | utility/crossystem_main.c | 1 |
2 files changed, 51 insertions, 4 deletions
diff --git a/host/lib/crossystem.c b/host/lib/crossystem.c index 5951e10b..17f4f505 100644 --- a/host/lib/crossystem.c +++ b/host/lib/crossystem.c @@ -54,6 +54,10 @@ #define BINF0_S3_RESUME_FAILED 10 /* Recovery caused by TPM error */ #define BINF0_RECOVERY_TPM_ERROR 11 +/* Firmware types from BINF.3 */ +#define BINF3_RECOVERY 0 +#define BINF3_NORMAL 1 +#define BINF3_DEVELOPER 2 /* Base name for ACPI files */ #define ACPI_BASE_PATH "/sys/devices/platform/chromeos_acpi" @@ -69,9 +73,12 @@ #define GPIO_BASE_PATH "/sys/class/gpio" #define GPIO_EXPORT_PATH GPIO_BASE_PATH "/export" -/* Base name for NVRAM file */ +/* Filename for NVRAM file */ #define NVRAM_PATH "/dev/nvram" +/* Filename for kernel command line */ +#define KERNEL_CMDLINE_PATH "/proc/cmdline" + /* Copy up to dest_size-1 characters from src to dest, ensuring null termination (which strncpy() doesn't do). Returns the destination @@ -414,11 +421,11 @@ const char* VbReadMainFwType(char* dest, int size) { /* Try reading type from BINF.3 */ switch(ReadFileInt(ACPI_BINF_PATH ".3")) { - case 0: + case BINF3_RECOVERY: return StrCopy(dest, "recovery", size); - case 1: + case BINF3_NORMAL: return StrCopy(dest, "normal", size); - case 2: + case BINF3_DEVELOPER: return StrCopy(dest, "developer", size); default: break; /* Fall through to legacy handling */ @@ -450,6 +457,43 @@ const char* VbReadMainFwType(char* dest, int size) { } +/* Determine whether OS-level debugging should be allowed. Passed the + * destination and its size. Returns 1 if yes, 0 if no, -1 if error. */ +int VbGetCrosDebug(void) { + FILE* f = NULL; + char buf[4096] = ""; + int binf3; + char *t, *saveptr; + + /* Try reading firmware type from BINF.3. */ + binf3 = ReadFileInt(ACPI_BINF_PATH ".3"); + if (BINF3_RECOVERY == binf3) + return 0; /* Recovery mode never allows debug. */ + else if (BINF3_DEVELOPER == binf3) + return 1; /* Developer firmware always allows debug. */ + + /* Normal new firmware, older ChromeOS firmware, or non-Chrome firmware. + * For all these cases, check /proc/cmdline for cros_debug. */ + f = fopen(KERNEL_CMDLINE_PATH, "rt"); + if (f) { + if (NULL == fgets(buf, sizeof(buf), f)) + *buf = 0; + fclose(f); + } + for (t = strtok_r(buf, " ", &saveptr); t; t=strtok_r(NULL, " ", &saveptr)) { + if (0 == strcmp(t, "cros_debug")) + return 1; + } + + /* Normal new firmware or older Chrome OS firmware allows debug if the + * dev switch is on. */ + if (1 == ReadFileBit(ACPI_CHSW_PATH, CHSW_DEV_BOOT)) + return 1; + + /* All other cases disallow debug. */ + return 0; +} + /* Read a system property integer. * @@ -512,6 +556,8 @@ int VbGetSystemPropertyInt(const char* name) { return VbGetRecoveryReason(); } else if (!strcasecmp(name,"fmap_base")) { value = ReadFileInt(ACPI_FMAP_PATH); + } else if (!strcasecmp(name,"cros_debug")) { + value = VbGetCrosDebug(); } return value; diff --git a/utility/crossystem_main.c b/utility/crossystem_main.c index 35d6ea70..584de594 100644 --- a/utility/crossystem_main.c +++ b/utility/crossystem_main.c @@ -34,6 +34,7 @@ const Param sys_param_list[] = { {"savedmem_size", 0, 0, "RAM debug data area size in bytes"}, {"fmap_base", 0, 0, "Main firmware flashmap physical address", "0x%08x"}, {"tried_fwb", 0, 0, "Tried firmware B before A this boot"}, + {"cros_debug", 0, 0, "OS should allow debug features"}, /* Read-only strings */ {"hwid", 1, 0, "Hardware ID"}, {"fwid", 1, 0, "Active firmware ID"}, |