Basic API for SMC handlers.

exosphere/smc_api.c

@@ -0,0 +1,137 @@
+#include <stdint.h>
+
+#include "utils.h"
+#include "smc_api.h"
+
+#define SMC_USER_HANDLERS 0x13
+#define SMC_PRIV_HANDLERS 0x9
+
+/* User SMC prototypes */
+uint32_t smc_set_config(smc_args_t *args);
+uint32_t smc_get_config(smc_args_t *args);
+uint32_t smc_check_status(smc_args_t *args);
+uint32_t smc_get_result(smc_args_t *args);
+uint32_t smc_exp_mod(smc_args_t *args);
+uint32_t smc_get_random_bytes_for_user(smc_args_t *args);
+uint32_t smc_generate_aes_kek(smc_args_t *args);
+uint32_t smc_load_aes_key(smc_args_t *args);
+uint32_t smc_crypt_aes(smc_args_t *args);
+uint32_t smc_generate_specific_aes_key(smc_args_t *args);
+uint32_t smc_compute_cmac(smc_args_t *args);
+uint32_t smc_load_rsa_private_key(smc_args_t *args);
+uint32_t smc_decrypt_rsa_private_key(smc_args_t *args);
+uint32_t smc_load_rsa_oaep_key(smc_args_t *args);
+uint32_t smc_rsa_oaep(smc_args_t *args);
+uint32_t smc_unwrap_rsa_wrapped_titlekey(smc_args_t *args);
+uint32_t smc_load_titlekey(smc_args_t *args);
+uint32_t smc_unwrap_aes_wrapped_titlekey(smc_args_t *args);
+
+/* Privileged SMC prototypes */
+uint32_t smc_cpu_suspend(smc_args_t *args);
+uint32_t smc_cpu_off(smc_args_t *args);
+uint32_t smc_cpu_on(smc_args_t *args);
+/* uint32_t smc_get_config(smc_args_t *args); */
+uint32_t smc_get_random_bytes_for_priv(smc_args_t *args);
+uint32_t smc_panic(smc_args_t *args);
+uint32_t smc_configure_carveout(smc_args_t *args);
+uint32_t smc_read_write_register(smc_args_t *args);
+
+typedef struct {
+    uint32_t id;
+    uint32_t (*handler)(smc_args_t *args);
+} smc_table_entry_t;
+
+typedef struct {
+    smc_table_entry_t *handlers;
+    uint32_t num_handlers;
+} smc_table_t;
+
+smc_table_entry_t g_smc_user_table[SMC_USER_HANDLERS] = {
+    {0, NULL},
+    {0xC3000401, smc_set_config},
+    {0xC3000002, smc_get_config},
+    {0xC3000003, smc_check_status},
+    {0xC3000404, smc_get_result},
+    {0xC3000E05, smc_exp_mod},
+    {0xC3000006, smc_get_random_bytes_for_user},
+    {0xC3000007, smc_generate_aes_kek},
+    {0xC3000008, smc_load_aes_key},
+    {0xC3000009, smc_crypt_aes},
+    {0xC300000A, smc_generate_specific_aes_key},
+    {0xC300040B, smc_compute_cmac},
+    {0xC300100C, smc_load_rsa_private_key},
+    {0xC300100D, smc_decrypt_rsa_private_key},
+    {0xC300100E, smc_load_rsa_oaep_key},
+    {0xC300060F, smc_rsa_oaep},
+    {0xC3000610, smc_unwrap_rsa_wrapped_titlekey},
+    {0xC3000011, smc_load_titlekey},
+    {0xC3000012, smc_unwrap_aes_wrapped_titlekey}
+};
+
+smc_table_entry_t g_smc_priv_table[SMC_PRIV_HANDLERS] = {
+    {0, NULL},
+    {0xC4000001, smc_cpu_suspend},
+    {0x84000002, smc_cpu_off},
+    {0xC4000003, smc_cpu_on},
+    {0xC3000004, smc_get_config}, /* NOTE: Same function as for USER */
+    {0xC3000005, smc_get_random_bytes_for_priv},
+    {0xC3000006, smc_panic},
+    {0xC3000007, smc_configure_carveout},
+    {0xC3000008, smc_read_write_register}
+};
+
+smc_table_t g_smc_tables[2] = {
+    { /* SMC_HANDLER_USER */
+        g_smc_user_table,
+        SMC_USER_HANDLERS
+    },
+    { /* SMC_HANDLER_PRIV */
+        g_smc_priv_table,
+        SMC_PRIV_HANDLERS
+    }
+};
+
+int g_is_smc_in_progress = 0;
+
+void call_smc_handler(uint32_t handler_id, smc_args_t *args) {
+    unsigned char smc_id;
+    unsigned int result;
+    unsigned int (*smc_handler)(smc_args_t *args);
+    
+    /* Validate top-level handler. */
+    if (handler_id != SMC_HANDLER_USER && handler_id != SMC_HANDLER_PRIV) {
+        panic();
+    }
+    
+    /* Validate sub-handler index */
+    if ((smc_id = (unsigned char)args->X[0]) >= g_smc_tables[handler_id].num_handlers) {
+        panic();
+    }
+    
+    /* Validate sub-handler */
+    if (g_smc_tables[handler_id].handlers[smc_id].id != args->X[0]) {
+        panic();
+    }
+    
+    /* Validate handler. */
+    if ((smc_handler = g_smc_tables[handler_id].handlers[smc_id].handler) == NULL) {
+        panic();
+    }
+    
+    /* Call function. */
+    args->X[0] = smc_handler(args);
+}
+
+uint32_t smc_wrapper_sync(smc_args_t *args, uint32_t (*handler)(smc_args_t *)) {
+    uint32_t result;
+    /* TODO: Make g_is_smc_in_progress atomic. */
+    if (g_is_smc_in_progress) {
+        return 3;
+    }
+    g_is_smc_in_progress = 1;
+    result = handler(args);
+    g_is_smc_in_progress = 0;
+    return result;
+}
+
+uint32_t smc_wrapper_async(smc_args_t *args, uint32_t (*handler)(smc_args_t *), uint32_t (*callback)(void, void));

exosphere/smc_api.h

@@ -0,0 +1,15 @@
+#ifndef EXOSPHERE_SMC_API_H
+#define EXOSPHERE_SMC_API_H
+
+#include <stdint.h>
+
+#define SMC_HANDLER_USER 0
+#define SMC_HANDLER_PRIV 1
+
+typedef struct {
+    uint64_t X[8];
+} smc_args_t;
+
+void call_smc_handler(unsigned int handler_id, smc_args_t *args);
+
+#endif