diff --git a/exosphere/se.c b/exosphere/se.c
new file mode 100644
index 000000000..f2b40a00e
--- /dev/null
+++ b/exosphere/se.c
@@ -0,0 +1,189 @@
+#include <stdint.h>
+
+#include "utils.h"
+#include "se.h"
+
+void trigger_se_rsa_op(void *buf, unsigned int size);
+void trigger_se_aes_op(unsigned int op, char *dst, unsigned int dst_size, const unsigned char *src, unsigned int src_size);
+
+/* Globals for driver. */
+security_engine_t *g_security_engine;
+
+unsigned int (*g_se_callback)(void);
+
+unsigned int g_se_modulus_sizes[KEYSLOT_RSA_MAX];
+unsigned int g_se_exp_sizes[KEYSLOT_RSA_MAX];
+
+/* Set the global security engine pointer. */
+void set_security_engine_address(security_engine_t *security_engine) {
+    g_security_engine = security_engine;
+}
+
+void set_security_engine_callback(unsigned int (*callback)(void)) {
+    if (callback == NULL || g_se_callback != NULL) {
+        panic();
+    }
+    
+    g_se_callback = callback;
+}
+
+/* Set the flags for an AES keyslot. */
+void set_aes_keyslot_flags(unsigned int keyslot, unsigned int flags) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX) {
+        panic();
+    }
+    
+    /* Misc flags. */
+    if (flags & ~0x80) {
+        g_security_engine->AES_KEYSLOT_FLAGS[keyslot] = ~flags;
+    }
+    
+    /* Disable keyslot reads. */
+    if (flags & 0x80) {
+        g_security_engine->AES_KEY_READ_DISABLE_REG &= ~(1 << keyslot);
+    }
+}
+
+/* Set the flags for an RSA keyslot. */
+void set_rsa_keyslot_flags(unsigned int keyslot, unsigned int flags) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_RSA_MAX) {
+        panic();
+    }
+    
+    /* Misc flags. */
+    if (flags & ~0x80) {
+        /* TODO: Why are flags assigned this way? */
+        g_security_engine->RSA_KEYSLOT_FLAGS[keyslot] = (((flags >> 4) & 4) | (flags & 3)) ^ 7;
+    }
+    
+    /* Disable keyslot reads. */
+    if (flags & 0x80) {
+        g_security_engine->RSA_KEY_READ_DISABLE_REG &= ~(1 << keyslot);
+    }
+}
+
+void clear_aes_keyslot(unsigned int keyslot) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX) {
+        panic();
+    }
+    
+    /* Zero out the whole keyslot and IV. */
+    for (unsigned int i = 0; i < 0x10; i++) {
+        g_security_engine->AES_KEYTABLE_ADDR = (keyslot << 4) | i;
+        g_security_engine->AES_KEYTABLE_DATA = 0;
+    }
+}
+
+void clear_rsa_keyslot(unsigned int keyslot) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_RSA_MAX) {
+        panic();
+    }
+    
+    /* Zero out the whole keyslot. */
+    for (unsigned int i = 0; i < 0x40; i++) {
+        /* Select Keyslot Modulus[i] */
+        g_security_engine->RSA_KEYTABLE_ADDR = (keyslot << 7) | i | 0x40;
+        g_security_engine->RSA_KEYTABLE_DATA = 0;
+    }
+    for (unsigned int i = 0; i < 0x40; i++) {
+        /* Select Keyslot Expontent[i] */
+        g_security_engine->RSA_KEYTABLE_ADDR = (keyslot << 7) | i;
+        g_security_engine->RSA_KEYTABLE_DATA = 0;
+    }
+}
+
+void set_aes_keyslot(unsigned int keyslot, const unsigned char *key, unsigned int key_size) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX || key_size > KEYSIZE_AES_MAX) {
+        panic();
+    }
+    
+    for (unsigned int i = 0; i < (key_size >> 2); i++) {
+        g_security_engine->AES_KEYTABLE_ADDR = (keyslot << 4) | i;
+        g_security_engine->AES_KEYTABLE_DATA = read32le(key, 4 * i);
+    }
+}
+
+void set_rsa_keyslot(unsigned int keyslot, const unsigned char *modulus, unsigned int modulus_size, const unsigned char *exp, unsigned int exp_size) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_RSA_MAX || modulus_size > KEYSIZE_RSA_MAX || exp_size > KEYSIZE_RSA_MAX) {
+        panic();
+    }
+    
+    for (unsigned int i = 0; i < (modulus_size >> 2); i++) {
+        g_security_engine->RSA_KEYTABLE_ADDR = (keyslot << 7) | 0x40 | i;
+        g_security_engine->RSA_KEYTABLE_DATA = read32be(modulus, 4 * i);
+    }
+    
+    for (unsigned int i = 0; i < (exp_size >> 2); i++) {
+        g_security_engine->RSA_KEYTABLE_ADDR = (keyslot << 7) | i;
+        g_security_engine->RSA_KEYTABLE_DATA = read32be(exp, 4 * i);
+    }
+    
+    g_se_modulus_sizes[keyslot] = modulus_size;
+    g_se_exp_sizes[keyslot] = exp_size;
+}
+
+
+void set_aes_keyslot_iv(unsigned int keyslot, const unsigned char *iv, unsigned int iv_size) {
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_AES_MAX || iv_size > 0x10) {
+        panic();
+    }
+    
+    for (unsigned int i = 0; i < (iv_size >> 2); i++) {
+        g_security_engine->AES_KEYTABLE_ADDR = (keyslot << 4) | 8 | i;
+        g_security_engine->AES_KEYTABLE_DATA = read32le(iv, 4 * i);
+    }
+}
+
+void set_se_ctr(const char *ctr) {
+    if (g_security_engine == NULL) {
+        panic();
+    }
+    
+    for (unsigned int i = 0; i < 4; i++) {
+        g_security_engine->CRYPTO_CTR_REG[i] = read32le(ctr, i * 4);
+    }
+}
+
+void decrypt_data_into_keyslot(unsigned int keyslot_dst, unsigned int keyslot_src, const unsigned char *wrapped_key, unsigned int wrapped_key_size) {
+    if (g_security_engine == NULL || keyslot_dst >= KEYSLOT_AES_MAX || keyslot_src >= KEYSIZE_AES_MAX || wrapped_key_size > KEYSIZE_AES_MAX) {
+        panic();
+    }
+    
+    g_security_engine->CONFIG_REG = (ALG_AES_DEC | DST_KEYTAB);
+    g_security_engine->CRYPTO_REG = keyslot_src << 24;
+    g_security_engine->BLOCK_COUNT_REG = 0;
+    g_se_callback->CRYPTO_KEYTABLE_DST_REG = keyslot_dst << 8;
+    
+    /* TODO: Cache flush the wrapped key. */
+    
+    trigger_se_aes_op(OP_START, NULL, 0, wrapped_key, wrapped_key_size);
+}
+
+
+void se_crypt_aes(unsigned int keyslot, unsigned char *dst, unsigned int dst_size, const unsigned char *src, unsigned int src_size, unsigned int config, unsigned int mode, unsigned int (*callback)(void));
+
+void se_exp_mod(unsigned int keyslot, unsigned char *buf, unsigned int size, unsigned int (*callback)(void)) {
+    unsigned char stack_buf[KEYSIZE_RSA_MAX];
+    
+    if (g_security_engine == NULL || keyslot >= KEYSLOT_RSA_MAX || size > KEYSIZE_RSA_MAX) {
+        panic();
+    }
+    
+    /* Endian swap the input. */
+    for (unsigned int i = size; i > 0; i--) {
+        stack_buf[i] = buf[size - i];
+    }
+    
+    /* TODO: Flush cache for stack copy. */
+    
+    g_security_engine->CONFIG_REG = (ALG_RSA | DST_RSAREG);
+    g_security_engine->RSA_CONFIG = keyslot << 24;
+    g_security_engine->RSA_KEY_SIZE_REG = (g_se_modulus_sizes[keyslot] >> 6) - 1;
+    g_security_engine->RSA_EXP_SIZE_REG = g_se_exp_sizes[keyslot] >> 2;
+    
+    set_security_engine_callback(callback);
+    
+    trigger_se_rsa_op(stack_buf, size);
+    
+    while (!(g_security_engine->INT_STATUS_REG & 2)) { /* Wait a while */ }
+}
\ No newline at end of file
diff --git a/exosphere/se.h b/exosphere/se.h
index 19569a5e5..1f4f97d05 100644
--- a/exosphere/se.h
+++ b/exosphere/se.h
@@ -3,12 +3,94 @@
 
 /* Exosphere driver for the Tegra X1 security engine. */
 
+#define KEYSLOT_AES_MAX 0x10
+#define KEYSLOT_RSA_MAX 0x2
+
+#define KEYSIZE_AES_MAX 0x20
+#define KEYSIZE_RSA_MAX 0x100
+
+#define ALG_SHIFT (12)
+#define ALG_DEC_SHIFT (8)
+#define ALG_NOP (0 << ALG_SHIFT)
+#define ALG_AES_ENC (1 << ALG_SHIFT)
+#define ALG_AES_DEC ((1 << ALG_DEC_SHIFT) | ALG_NOP)
+#define ALG_RNG (2 << ALG_SHIFT)
+#define ALG_SHA (3 << ALG_SHIFT)
+#define ALG_RSA (4 << ALG_SHIFT)
+
+#define DST_SHIFT (2)
+#define DST_MEMORY (0 << DST_SHIFT)
+#define DST_HASHREG (1 << DST_SHIFT)
+#define DST_KEYTAB (2 << DST_SHIFT)
+#define DST_SRK (3 << DST_SHIFT)
+#define DST_RSAREG (4 << DST_SHIFT)
+
+
+
+#define OP_ABORT 0
+#define OP_START 1
+#define OP_RESTART 2
+#define OP_CTX_SAVE 3
+#define OP_RESTART_IN 4
+
+
+typedef struct security_engine {
+  unsigned int _0x0;
+  unsigned int _0x4;
+  unsigned int OPERATION_REG;
+  unsigned int INT_ENABLE_REG;
+  unsigned int INT_STATUS_REG;
+  unsigned int CONFIG_REG;
+  unsigned int IN_LL_ADDR_REG;
+  unsigned int _0x1C;
+  unsigned int _0x20;
+  unsigned int OUT_LL_ADDR_REG;
+  unsigned int _0x28;
+  unsigned int _0x2C;
+  unsigned char cmacOutput[0x10];
+  unsigned char reserved0x40[0x240];
+  unsigned int AES_KEY_READ_DISABLE_REG;
+  unsigned int AES_KEYSLOT_FLAGS[0x10];
+  unsigned char _0x2C4[0x3C];
+  unsigned int _0x300;
+  unsigned int CRYPTO_REG;
+  unsigned int CRYPTO_CTR_REG[4];
+  unsigned int BLOCK_COUNT_REG;
+  unsigned int AES_KEYTABLE_ADDR;
+  unsigned int AES_KEYTABLE_DATA;
+  unsigned int _0x324;
+  unsigned int _0x328;
+  unsigned int _0x32C;
+  unsigned int CRYPTO_KEYTABLE_DST_REG;
+  unsigned char _0x334[0xCC];
+  unsigned int RSA_CONFIG;
+  unsigned int RSA_KEY_SIZE_REG;
+  unsigned int RSA_EXP_SIZE_REG;
+  unsigned int RSA_KEY_READ_DISABLE_REG;
+  unsigned int RSA_KEYSLOT_FLAGS[2];
+  unsigned int _0x418;
+  unsigned int _0x41C;
+  unsigned int RSA_KEYTABLE_ADDR;
+  unsigned int RSA_KEYTABLE_DATA;
+  unsigned int RSA_OUTPUT;
+  unsigned char _0x42C[0x3D4];
+  unsigned int FLAGS_REG;
+  unsigned int ERR_STATUS_REG;
+  unsigned int _0x808;
+  unsigned int _0x80C;
+  unsigned int _0x810;
+  unsigned int _0x814;
+  unsigned int _0x818;
+  unsigned int _0x81C;
+  unsigned char _0x820[0x17E0];
+} security_engine_t;
+
 /* TODO: Define constants for the C driver. */
 
+
 /* WIP, API subject to change. */
 
-#define KEYSLOT_AES_MAX 0x10
-#define KEYSLOT_RSA_MAX 0x2
+
 
 void set_security_engine_address(void *security_engine);
 
@@ -17,14 +99,14 @@ void set_rsa_keyslot_flags(unsigned int keyslot, unsigned int flags);
 void clear_aes_keyslot(unsigned int keyslot);
 void clear_rsa_keyslot(unsigned int keyslot);
 
-void set_aes_keyslot(unsigned int keyslot, const char *key, unsigned int key_size);
-void crypt_data_into_keyslot(unsigned int keyslot_dst, unsigned int keyslot_src, const char *wrapped_key, unsigned int wrapped_key_size);
-void set_rsa_keyslot(unsigned int keyslot, const char *modulus, unsigned int modulus_size, const char *exp, unsigned int exp_size);
-void set_aes_keyslot_iv(unsigned int keyslot, const char *iv, unsigned int iv_size);
-void set_se_ctr(const unsigned int *ctr);
+void set_aes_keyslot(unsigned int keyslot, const unsigned char *key, unsigned int key_size);
+void decrypt_data_into_keyslot(unsigned int keyslot_dst, unsigned int keyslot_src, const unsigned char *wrapped_key, unsigned int wrapped_key_size);
+void set_rsa_keyslot(unsigned int keyslot, const unsigned char *modulus, unsigned int modulus_size, const unsigned char *exp, unsigned int exp_size);
+void set_aes_keyslot_iv(unsigned int keyslot, const unsigned char *iv, unsigned int iv_size);
+void set_se_ctr(const char *ctr);
 
-void se_crypt_aes(unsigned int keyslot, char *dst, unsigned int dst_size, const char *src, unsigned int src_size, unsigned int config, unsigned int mode, unsigned int (*callback)(void));
-void se_exp_mod(unsigned int keyslot, char *buf, unsigned int size, unsigned int (*callback)(void));
+void se_crypt_aes(unsigned int keyslot, unsigned char *dst, unsigned int dst_size, const unsigned char *src, unsigned int src_size, unsigned int config, unsigned int mode, unsigned int (*callback)(void));
+void se_exp_mod(unsigned int keyslot, unsigned char *buf, unsigned int size, unsigned int (*callback)(void));
 
 /* TODO: SE context save API, consider extending AES API for secure world vs non-secure world operations. */
 /* In particular, smc_crypt_aes takes in raw DMA lists, and we need to support that. */
diff --git a/exosphere/utils.h b/exosphere/utils.h
new file mode 100644
index 000000000..3ba7bd2f6
--- /dev/null
+++ b/exosphere/utils.h
@@ -0,0 +1,9 @@
+#ifndef EXOSPHERE_UTILS_H
+#define EXOSPHERE_UTILS_H
+
+void panic(void);
+
+unsigned int read32le(const unsigned char *dword, unsigned int offset);
+unsigned int read32be(const unsigned char *dword, unsigned int offset);
+
+#endif
\ No newline at end of file