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TSEC (view source)

Revision as of 18:12, 21 November 2018

9,741 bytes added ,  18:12, 21 November 2018
6.2.0 changes
Line 392: Line 392:  
| TSEC_TFBIF_UNK2
 
| TSEC_TFBIF_UNK2
 
| 0x54501640
 
| 0x54501640
 +
| 0x04
 +
|-
 +
| TSEC_TFBIF_UNK3
 +
| 0x54501644
 +
| 0x04
 +
|-
 +
| TSEC_TFBIF_UNK4
 +
| 0x54501648
 
| 0x04
 
| 0x04
 
|-
 
|-
Line 429: Line 437:  
| 0x54501838
 
| 0x54501838
 
| 0x04
 
| 0x04
−
|-
   
|}
 
|}
   Line 454: Line 461:  
| 1
 
| 1
 
| FALCON_ITFEN_MTHDEN
 
| FALCON_ITFEN_MTHDEN
−
|-
   
|}
 
|}
   Line 466: Line 472:  
| 0
 
| 0
 
| FALCON_IDLESTATE_FALCON_BUSY
 
| FALCON_IDLESTATE_FALCON_BUSY
−
|-
   
|}
 
|}
   Line 493: Line 498:  
| 5
 
| 5
 
| FALCON_CPUCTL_STOPPED
 
| FALCON_CPUCTL_STOPPED
−
|-
   
|}
 
|}
   Line 520: Line 524:  
| 7
 
| 7
 
| FALCON_DMACTL_SECURE_STAT
 
| FALCON_DMACTL_SECURE_STAT
−
|-
   
|}
 
|}
   Line 540: Line 543:  
|-
 
|-
 
| 1
 
| 1
−
| FALCON_DMATRFCMD_IDLE (this is set if the engine is idle)
+
| FALCON_DMATRFCMD_IDLE
 
|-
 
|-
 
| 2-3
 
| 2-3
Line 556: Line 559:  
| 12-14
 
| 12-14
 
| FALCON_DMATRFCMD_CTXDMA
 
| FALCON_DMATRFCMD_CTXDMA
−
|-
   
|}
 
|}
   Line 571: Line 573:  
| 20
 
| 20
 
| TSEC_SCP_CTL_STAT_DEBUG_MODE
 
| TSEC_SCP_CTL_STAT_DEBUG_MODE
−
|-
   
|}
 
|}
   Line 584: Line 585:  
| 1
 
| 1
 
| TSEC_SCP_CTL_PKEY_LOADED
 
| TSEC_SCP_CTL_PKEY_LOADED
−
|-
   
|}
 
|}
   Line 609: Line 609:  
| 31
 
| 31
 
| TSEC_DMA_CMD_INIT
 
| TSEC_DMA_CMD_INIT
−
|-
   
|}
 
|}
   Line 649: Line 648:  
| 27
 
| 27
 
| TSEC_TEGRA_CTL_TMPI_DISABLE_OUTPUT_I2C
 
| TSEC_TEGRA_CTL_TMPI_DISABLE_OUTPUT_I2C
−
|-
   
|}
 
|}
    
= Boot Process =
 
= Boot Process =
−
TSEC is configured and initialized by the first bootloader during key generation (sub_400114FC).
+
TSEC is configured and initialized by the first bootloader during key generation.
 +
 
 +
[6.2.0+] TSEC is now configured at the end of the first bootloader's main function.
    
== Initialization ==
 
== Initialization ==
Line 709: Line 709:  
  // Load code into Falcon (0x100 bytes at a time)
 
  // Load code into Falcon (0x100 bytes at a time)
 
  while (src_offset < 0xF00)
 
  while (src_offset < 0xF00)
 +
{
 +
    flcn_load_firm(trf_mode, src_offset, dst_offset);
 +
    src_offset += 0x100;
 +
    dst_offset += 0x100;
 +
}
 +
 +
[6.2.0+] The transfer base address and size of the Falcon firmware code changed.
 +
// Set DMA transfer base address to 0x40010E00 >> 0x08
 +
*(u32 *)FALCON_DMATRFBASE = 0x40010E;
 +
 +
u32 trf_mode = 0;    // A value of 0 sets FALCON_DMATRFCMD_IMEM
 +
u32 dst_offset = 0;
 +
u32 src_offset = 0;
 +
 +
// Load code into Falcon (0x100 bytes at a time)
 +
while (src_offset < 0x2900)
 
  {
 
  {
 
     flcn_load_firm(trf_mode, src_offset, dst_offset);
 
     flcn_load_firm(trf_mode, src_offset, dst_offset);
Line 717: Line 733:  
== Firmware booting ==
 
== Firmware booting ==
 
Falcon is booted up and the first bootloader waits for it to finish.
 
Falcon is booted up and the first bootloader waits for it to finish.
−
  // Set something in unknown host1x channel 0 sync register (HOST1X_SYNC_UNK_300)
+
  // Set magic value in host1x scratch space
−
// This appears to grant TSEC exclusive access to host1x
   
  *(u32 *)0x50003300 = 0x34C2E1DA;
 
  *(u32 *)0x50003300 = 0x34C2E1DA;
 
   
 
   
Line 757: Line 772:  
  if (boot_res != 0xB0B0B0B0)
 
  if (boot_res != 0xB0B0B0B0)
 
     panic();
 
     panic();
 +
 +
[6.2.0+] Falcon is booted up, but the first bootloader is left in an infinite loop.
 +
// Set magic value in host1x scratch space
 +
*(u32 *)0x50003300 = 0x34C2E1DA;
 +
 +
// Clear Falcon scratch1 MMIO
 +
*(u32 *)FALCON_SCRATCH1 = 0;
 +
 +
// Set Falcon boot key version in scratch0 MMIO
 +
*(u32 *)FALCON_SCRATCH0 = 0x01;
 +
 +
// Set Falcon's boot vector address
 +
*(u32 *)FALCON_BOOTVEC = 0;
 +
 +
// Signal Falcon's CPU
 +
*(u32 *)FALCON_CPUCTL = 0x02;
 +
 +
// Infinite loop
 +
deadlock();
    
== Device key generation ==
 
== Device key generation ==
 
The TSEC device key is generated by reading SOR1 registers modified by the Falcon CPU.
 
The TSEC device key is generated by reading SOR1 registers modified by the Falcon CPU.
−
  // Clear something in unknown host1x channel 0 sync register (HOST1X_SYNC_UNK_300)
+
  // Clear magic value in host1x scratch space
−
// This appears to revoke TSEC's exclusive access to host1x
   
  *(u32 *)0x50003300 = 0;
 
  *(u32 *)0x50003300 = 0;
 
   
 
   
Line 782: Line 815:  
  // Copy back the TSEC device key
 
  // Copy back the TSEC device key
 
  memcpy(out_buf, tsec_device_key, out_size);
 
  memcpy(out_buf, tsec_device_key, out_size);
 +
 +
[6.2.0+] This is now done inside an encrypted TSEC payload.
    
== Cleanup ==
 
== Cleanup ==
Line 813: Line 848:  
= TSEC Firmware =
 
= TSEC Firmware =
 
The actual code loaded into TSEC is assembled in NVIDIA's proprietary fuc5 ISA using crypto extensions.
 
The actual code loaded into TSEC is assembled in NVIDIA's proprietary fuc5 ISA using crypto extensions.
−
Stored inside the first bootloader, this firmware binary is split into 4 blobs: Stage0, Stage1, Stage2 and key data.
+
Stored inside the first bootloader, this firmware binary is split into 4 blobs (names are unofficial): [[#Boot|Boot]] (unencrypted and unauthenticated code), [[#KeygenLdr|KeygenLdr]] (unencrypted and authenticated code), [[#Keygen|Keygen]] (encrypted and authenticated code) and [[#Key data|key data]].
 +
 
 +
[6.2.0+] There are now 6 blobs (names are unofficial): [[#Boot|Boot]] (unencrypted and unauthenticated code), [[#Loader|Loader]] (unencrypted and unauthenticated code), [[#KeygenLdr|KeygenLdr]] (unencrypted and authenticated code), [[#Keygen|Keygen]] (encrypted and authenticated code), [[#Payload|Payload]] (part unencrypted and unauthenticated code, part encrypted and authenticated code) and [[#Key data|key data]].
    
Firmware can be disassembled with [http://envytools.readthedocs.io/en/latest/ envytools'] [https://github.com/envytools/envytools/tree/master/envydis envydis]:
 
Firmware can be disassembled with [http://envytools.readthedocs.io/en/latest/ envytools'] [https://github.com/envytools/envytools/tree/master/envydis envydis]:
Line 821: Line 858:  
Note that the instruction set has variable length instructions, and the disassembler is not very good at detecting locations it should start disassembling from. One needs to disassemble multiple sub-regions and join them together.
 
Note that the instruction set has variable length instructions, and the disassembler is not very good at detecting locations it should start disassembling from. One needs to disassemble multiple sub-regions and join them together.
   −
== Stage 0 ==
+
== Boot ==
−
During this stage key data is loaded and Stage 1 is authenticated, loaded and executed.
+
During this stage, [[#Key data|key data]] is loaded and [[#KeygenLdr|KeygenLdr]] is authenticated, loaded and executed.
 
Before returning, this stage writes back to the host (using MMIO registers) and sets the device key used by the first bootloader.
 
Before returning, this stage writes back to the host (using MMIO registers) and sets the device key used by the first bootloader.
 +
 +
[6.2.0+] During this stage, [[#Key data|key data]] is loaded and execution jumps to [[#Loader|Loader]].
    
=== Initialization ===
 
=== Initialization ===
Line 836: Line 875:  
  *(u32 *)sp = data_seg_size;
 
  *(u32 *)sp = data_seg_size;
   −
=== Stage 1 loading ===  
+
=== Main ===
 +
Falcon reads the [[#Key data|key data]], authenticates, loads and executes [[#KeygenLdr|KeygenLdr]] and finally sets the device key.
 
  u32 boot_base_addr = 0;
 
  u32 boot_base_addr = 0;
−
  u32 key_data_buf[0x7C];
+
  u8 key_data_buf[0x7C];
 
   
 
   
 
  // Read the key data from memory
 
  // Read the key data from memory
Line 908: Line 948:  
            
 
            
 
           // Transfer data to crypto register c6
 
           // Transfer data to crypto register c6
−
xdst(0, (blob1_hash_addr | crypt_reg_flag));
+
  xdst(0, (blob1_hash_addr | crypt_reg_flag));
 
   
 
   
−
// Wait for all data loads/stores to finish
+
  // Wait for all data loads/stores to finish
−
xdwait();
+
  xdwait();
 
            
 
            
−
           // Jump to Stage1
+
           // Jump to KeygenLdr
−
           u32 stage1_res = exec_stage1(key_buf, key_version, is_blob_dec);
+
           u32 keygenldr_res = exec_keygenldr(key_buf, key_version, is_blob_dec);
 
           is_blob_dec = true;  // Set this to prevent decrypting again
 
           is_blob_dec = true;  // Set this to prevent decrypting again
 
   
 
   
 
           // Set boot finish magic on success
 
           // Set boot finish magic on success
−
    if (stage1_res == 0)
+
    if (keygenldr_res == 0)
 
             boot_res = 0xB0B0B0B0
 
             boot_res = 0xB0B0B0B0
 
       }
 
       }
Line 936: Line 976:  
   
 
   
 
  return boot_res;
 
  return boot_res;
 +
 +
[6.2.0+] Falcon reads the [[#Key data|key data]] and jumps to [[#Loader|Loader]].
 +
u8 key_data_buf[0x84];
 +
 +
// Read the key data from memory
 +
u32 key_data_addr = 0x300;
 +
u32 key_data_size = 0x84;
 +
read_code(key_data_buf, key_data_addr, key_data_size);
 +
 +
// Calculate the next blob's address
 +
u32 blob4_size = *(u32 *)(key_data_buf + 0x80);
 +
u32 blob0_size = *(u32 *)(key_data_buf + 0x70);
 +
u32 blob1_size = *(u32 *)(key_data_buf + 0x74);
 +
u32 blob2_size = *(u32 *)(key_data_buf + 0x78);
 +
u32 blob3_addr = ((((blob0_size + blob1_size) + 0x100) + blob2_size) + blob4_size);
 +
 +
// Jump to next blob
 +
(void *)blob3_addr();
 +
 
 +
return 0;
    
==== set_device_key ====
 
==== set_device_key ====
Line 1,014: Line 1,074:  
  return 0;
 
  return 0;
   −
== Stage 1 ==
+
== KeygenLdr ==
−
This stage is responsible for reconfiguring the Falcon's crypto co-processor and loading, decrypting, authenticating and executing Stage 2.
+
This stage is responsible for reconfiguring the Falcon's crypto co-processor and loading, decrypting, authenticating and executing [[#Keygen|Keygen]].
   −
=== Crypto setup ===
+
=== Main ===
 
  // Clear interrupt flags
 
  // Clear interrupt flags
 
  *(u8 *)flags_ie0 = 0;
 
  *(u8 *)flags_ie0 = 0;
Line 1,085: Line 1,145:  
   exit();
 
   exit();
 
   
 
   
−
  // Decrypt and load Stage2
+
  // Decrypt and load Keygen stage
−
  load_stage2(key_buf, key_version, is_blob_dec);
+
  load_keygen(key_buf, key_version, is_blob_dec);
 
   
 
   
 
  // Partially unknown fuc5 instruction
 
  // Partially unknown fuc5 instruction
Line 1,108: Line 1,168:  
  return;
 
  return;
   −
=== Stage 2 loading ===
+
==== load_keygen ====
 
  u32 res = 0;
 
  u32 res = 0;
 
   
 
   
Line 1,119: Line 1,179:  
   
 
   
 
  // Generate "CODE_SIG_01" key into c4 crypto register
 
  // Generate "CODE_SIG_01" key into c4 crypto register
−
  keygen(0, 0);
+
  gen_usr_key(0, 0);
 
   
 
   
 
  // Encrypt buffer with c4
 
  // Encrypt buffer with c4
−
  u32 sig_key[0x10];
+
  u8 sig_key[0x10];
 
  enc_buf(sig_key, blob0_size);
 
  enc_buf(sig_key, blob0_size);
 
   
 
   
Line 1,144: Line 1,204:  
  u32 blob1_size = *(u32 *)(key_buf + 0x74);
 
  u32 blob1_size = *(u32 *)(key_buf + 0x74);
 
   
 
   
−
  // Decrypt Stage2 blob if needed
+
  // Decrypt Keygen blob if needed
 
  if (!is_blob_dec)
 
  if (!is_blob_dec)
 
  {
 
  {
Line 1,157: Line 1,217:  
       u32 blob2_addr = blob2_virt_addr + 0x100;
 
       u32 blob2_addr = blob2_virt_addr + 0x100;
 
        
 
        
−
       // Read Stage2's encrypted blob
+
       // Read Keygen encrypted blob
 
       read_code(boot_base_addr, blob2_addr, blob2_size);
 
       read_code(boot_base_addr, blob2_addr, blob2_size);
 
   
 
   
 
       // Generate "CODE_ENC_01" key into c4 crypt register
 
       // Generate "CODE_ENC_01" key into c4 crypt register
−
       keygen(0x01, 0x01);
+
       gen_usr_key(0x01, 0x01);
 
        
 
        
 
       u32 src_addr = boot_base_addr;
 
       u32 src_addr = boot_base_addr;
Line 1,170: Line 1,230:  
       u32 version = 0;
 
       u32 version = 0;
 
        
 
        
−
       // Decrypt Stage2
+
       // Decrypt Keygen blob
 
       do_crypto(src_addr, src_size, iv_addr, dst_addr, mode, version);
 
       do_crypto(src_addr, src_size, iv_addr, dst_addr, mode, version);
 
        
 
        
Line 1,215: Line 1,275:  
   res = 0xD0D0D0D0
 
   res = 0xD0D0D0D0
 
 
 
 
−
  // Jump to Stage2
+
  // Jump to Keygen
 
  if (hovi_key_addr)
 
  if (hovi_key_addr)
−
   res = exec_stage2(hovi_key_addr, key_version);
+
   res = exec_keygen(hovi_key_addr, key_version);
 
            
 
            
 
  // Clear out key data
 
  // Clear out key data
Line 1,228: Line 1,288:  
  return res;
 
  return res;
   −
==== keygen ====
+
===== gen_usr_key =====
 
This method takes '''type''' and '''mode''' as arguments and generates a key.
 
This method takes '''type''' and '''mode''' as arguments and generates a key.
−
  u32 seed_buf[0x10];
+
  u8 seed_buf[0x10];
 
   
 
   
 
  // Read a 16 bytes seed based on supplied type
 
  // Read a 16 bytes seed based on supplied type
Line 1,267: Line 1,327:  
  return;
 
  return;
   −
==== enc_buffer ====
+
===== enc_buffer =====
 
This method takes '''buf''' (a 16 bytes buffer) and '''size''' as arguments and encrypts the supplied buffer.
 
This method takes '''buf''' (a 16 bytes buffer) and '''size''' as arguments and encrypts the supplied buffer.
 
  // Set first 3 words to null
 
  // Set first 3 words to null
Line 1,296: Line 1,356:  
  return;
 
  return;
   −
==== do_crypto ====
+
===== do_crypto =====
−
This is the method responsible for all crypto operations performed during Stage 1. It takes '''src_addr''', '''src_size''', '''iv_addr''', '''dst_addr''', '''mode''' and '''crypt_ver''' as arguments.
+
This is the method responsible for all crypto operations performed during [[#KeygenLdr|KeygenLdr]]. It takes '''src_addr''', '''src_size''', '''iv_addr''', '''dst_addr''', '''mode''' and '''crypt_ver''' as arguments.
 
  // Check for invalid source data size
 
  // Check for invalid source data size
 
  if (!src_size || (src_size & 0x0F))
 
  if (!src_size || (src_size & 0x0F))
Line 1,499: Line 1,559:  
  return;
 
  return;
   −
== Stage 2 ==
+
== Keygen ==
−
This stage is decrypted by Stage 1 using a key generated by encrypting a seed with an hardware secret (see [[TSEC#keygen|keygen]]).
+
This stage is decrypted by [[#KeygenLdr|KeygenLdr]] using a key generated by encrypting a seed with an hardware secret. It will generate the final TSEC device key.
 +
 
 +
== Loader ==
 +
This stage starts by authenticating and executing [[#KeygenLdr|KeygenLdr]] which in turn authenticates, decrypts and executes [[#Keygen|Keygen]] (both blobs remain unchanged from previous firmware versions).
 +
After the TSEC device key has been generated, execution returns to this stage which then parses and executes [[#Payload|Payload]].
 +
 
 +
=== Main ===
 +
u8 key_data_buf[0x84];
 +
u8 tmp_key_data_buf[0x84];
 +
 +
// Read the key data from memory
 +
u32 key_data_addr = 0x300;
 +
u32 key_data_size = 0x84;
 +
read_code(key_data_buf, key_data_addr, key_data_size);
 +
 +
// Read the KeygenLdr blob from memory
 +
u32 boot_base_addr = 0;
 +
u32 blob1_addr = 0x400;
 +
u32 blob1_size = *(u32 *)(key_data_buf + 0x74);
 +
read_code(boot_base_addr, blob1_addr, blob1_size);
 +
 
 +
// Upload the next code segment into Falcon's CODE region
 +
u32 blob1_virt_addr = 0x300;
 +
bool use_secret = true;
 +
upload_code(blob1_virt_addr, boot_base_addr, blob1_size, blob1_virt_addr, use_secret);
 +
 +
// Backup the key data
 +
memcpy(tmp_key_data_buf, key_data_buf, 0x84);
 +
 +
// Save previous cauth value
 +
u32 c_old = cauth_old;
 +
 +
// fuc5 crypt cauth instruction
 +
// Set auth_addr to 0x300 and auth_size to blob1_size
 +
cauth((blob1_size << 0x10) | (0x300 >> 0x08));
 +
 +
// fuc5 crypt cxset instruction
 +
// The next 2 xfer instructions will be overridden
 +
// and target changes from DMA to crypto
 +
cxset(0x02);
 +
 +
u32 crypt_reg_flag = 0x00060000;
 +
u32 blob1_hash_addr = tmp_key_data_buf + 0x20;
 +
 +
// Transfer data to crypto register c6
 +
xdst(0, (blob1_hash_addr | crypt_reg_flag));
 +
 +
// Wait for all data loads/stores to finish
 +
xdwait();
 +
 +
u32 key_version = 0x01;
 +
bool is_blob_dec = false;
 +
 +
// Jump to KeygenLdr
 +
u32 keygenldr_res = exec_keygenldr(tmp_key_data_buf, key_version, is_blob_dec);
 +
 +
// Set boot finish magic on success
 +
if (keygenldr_res == 0)
 +
  keygenldr_res = 0xB0B0B0B0
 +
     
 +
// Write result to FALCON_SCRATCH1
 +
*(u32 *)FALCON_SCRATCH1 = keygenldr_res;
 +
 +
if (keygenldr_res != 0xB0B0B0B0)
 +
  return keygenldr_res;
 +
 +
// fuc5 crypt cauth instruction
 +
// Restore previous cauth value
 +
cauth(c_old);
 +
 +
u8 flcn_hdr_buf[0x18];
 +
u8 flcn_os_hdr_buf[0x10];
 +
 +
blob1_size = *(u32 *)(key_data_buf + 0x74);
 +
u32 blob2_size = *(u32 *)(key_data_buf + 0x78);
 +
u32 blob0_size = *(u32 *)(key_data_buf + 0x70);
 +
 +
// Read the Payload blob's Falcon header from memory
 +
u32 blob4_flcn_hdr_addr = (((blob0_size + blob1_size) + 0x100) + blob2_size);
 +
read_code(flcn_hdr_buf, blob4_flcn_hdr_addr, 0x18);
 +
 +
blob1_size = *(u32 *)(key_data_buf + 0x74);
 +
blob2_size = *(u32 *)(key_data_buf + 0x78);
 +
blob0_size = *(u32 *)(key_data_buf + 0x70);
 +
u32 flcn_hdr_size = *(u32 *)(flcn_hdr_buf + 0x0C);
 +
 +
// Read the Payload blob's Falcon OS header from memory
 +
u32 blob4_flcn_os_hdr_addr = ((((blob0_size + blob1_size) + 0x100) + blob2_size) + flcn_hdr_size);
 +
read_code(flcn_os_hdr_buf, blob4_flcn_os_hdr_addr, 0x10);
 +
 +
blob1_size = *(u32 *)(key_data_buf + 0x74);
 +
blob2_size = *(u32 *)(key_data_buf + 0x78);
 +
blob0_size = *(u32 *)(key_data_buf + 0x70);
 +
u32 flcn_code_hdr_size = *(u32 *)(flcn_hdr_buf + 0x10);
 +
u32 flcn_os_size = *(u32 *)(flcn_os_hdr_buf + 0x04);
 +
 +
// Read the Payload blob's Falcon OS image from memory
 +
u32 blob4_flcn_os_addr = ((((blob0_size + blob1_size) + 0x100) + blob2_size) + flcn_code_hdr_size);
 +
read_code(boot_base_addr, blob4_flcn_os_hdr_addr, flcn_os_size);
 +
 +
// Upload the Payload's Falcon OS image boot stub code segment into Falcon's CODE region
 +
u32 blob4_flcn_os_boot_virt_addr = 0;
 +
u32 blob4_flcn_os_boot_size = 0x100;
 +
use_secret = false;
 +
upload_code(blob4_flcn_os_boot_virt_addr, boot_base_addr, blob4_flcn_os_boot_size, blob4_flcn_os_boot_virt_addr, use_secret);
 +
 +
flcn_os_size = *(u32 *)(flcn_os_hdr_buf + 0x04);
 +
 +
// Upload the Payload blob's Falcon OS encrypted image code segment into Falcon's CODE region
 +
u32 blob4_flcn_os_img_virt_addr = 0x100;
 +
u32 blob4_flcn_os_img_size = (flcn_os_size - 0x100);
 +
use_secret = true;
 +
upload_code(blob4_flcn_os_img_virt_addr, boot_base_addr + 0x100, blob4_flcn_os_img_size, blob4_flcn_os_img_virt_addr, use_secret);
 +
 +
// Wait for all code loads to finish
 +
xcwait();
 +
 +
blob1_size = *(u32 *)(key_data_buf + 0x74);
 +
blob2_size = *(u32 *)(key_data_buf + 0x78);
 +
blob0_size = *(u32 *)(key_data_buf + 0x70);
 +
flcn_code_hdr_size = *(u32 *)(flcn_hdr_buf + 0x10);
 +
u32 flcn_os_code_size = *(u32 *)(flcn_os_hdr_buf + 0x08);
 +
 +
// Read the Payload blob's falcon OS image's hash from memory
 +
u32 blob4_flcn_os_img_hash_addr = (((((blob0_size + blob1_size) + 0x100) + blob2_size) + flcn_code_hdr_size) + flcn_os_code_size);
 +
read_code(0, blob4_flcn_os_img_hash_addr, 0x10);
 +
 +
// Read data segment size from IO space
 +
u32 data_seg_size = *(u32 *)UC_CAPS;
 +
data_seg_size >>= 0x03;
 +
data_seg_size &= 0x3FC0;
 +
 +
u32 data_addr = 0x10;
 +
 +
// Clear all data except the first 0x10 bytes (Payload blob's Falcon OS image's hash)
 +
for (int data_word_count = 0x04; data_word_count < data_seg_size; data_word_count++)
 +
{
 +
  *(u32 *)(data_addr) = 0;
 +
  data_addr += 0x04;
 +
}
 +
 +
// Clear all crypto registers
 +
cxor(c0, c0);
 +
cxor(c1, c1);
 +
cxor(c2, c2);
 +
cxor(c3, c3);
 +
cxor(c4, c4);
 +
cxor(c5, c5);
 +
cxor(c6, c6);
 +
cxor(c7, c7);
 +
 +
// Partially unknown fuc5 instruction
 +
// Likely forces a change of permissions
 +
cchmod(c0, c0);
 +
 +
// Jump to Payload
 +
exec_payload();
 +
 +
return 0xB0B0B0B0;
 +
 
 +
== Payload ==
 +
This stage prepares the stack then authenticates, decrypts and executes the Payload blob's Falcon OS image.
 +
 
 +
=== Main ===
 +
// Read data segment size from IO space
 +
u32 data_seg_size = *(u32 *)UC_CAPS;
 +
data_seg_size >>= 0x01;
 +
data_seg_size &= 0xFF00;
 +
 +
// Set the stack pointer
 +
*(u32 *)sp = data_seg_size;
 +
 +
// Jump to the Payload blob's Falcon OS image boot stub
 +
exec_flcn_os_boot();
 +
 +
// Halt execution
 +
exit();
 +
 +
return;
 +
 
 +
==== exec_flcn_os_boot ====
 +
// Read the transfer base address from IO space
 +
u32 xfer_ext_base_addr = *(u32 *)XFER_EXT_BASE;
 +
 +
// Copy transfer base address to data memory
 +
u32 scratch_data_addr = 0x300;
 +
*(u32 *)scratch_data_addr = xfer_ext_base_addr;
 +
 +
// Set the transfer base address
 +
xcbase(xfer_ext_base_addr);
 +
 +
// fuc5 crypt cxset instruction
 +
// The next xfer instruction will be overridden
 +
// and target changes from DMA to crypto
 +
cxset(0x01);
 +
 +
u32 crypt_reg_flag = 0x00060000;
 +
u32 blob4_flcn_os_img_hash_addr = 0;
 +
 +
// Transfer data to crypto register c6
 +
xdst(0, (blob4_flcn_os_img_hash_addr | crypt_reg_flag));
 +
 +
// fuc5 crypt cxset instruction
 +
// The next xfer instruction will be overridden
 +
// and target changes from DMA to crypto
 +
cxset(0x01);
 +
 +
// Wait for all data loads/stores to finish
 +
xdwait();
 +
 +
cmov(c7, c6);
 +
cxor(c7, c7);
 +
 +
// fuc5 crypt cauth instruction
 +
// Set auth_addr to 0x100, auth_size to 0x1300 and some unknown flags
 +
cauth((0x02 << 0x10) | (0x01 << 0x10) | (0x1300 << 0x10) | (0x100 >> 0x08));
 +
 +
// Clear interrupt flags
 +
*(u8 *)flags_ie0 = 0;
 +
*(u8 *)flags_ie1 = 0;
 +
 +
// Jump to the Payload blob's Falcon OS image
 +
exec_flcn_os_img();
 +
 +
return 0x0F0F0F0F;
    
== Key data ==
 
== Key data ==
−
Small buffer stored after Stage 0's code and used across all stages.
+
Small buffer stored after the [[#Boot|Boot]] blob and used across all stages.
    
{| class="wikitable" border="1"
 
{| class="wikitable" border="1"
Line 1,516: Line 1,800:  
| 0x10
 
| 0x10
 
| 0x10
 
| 0x10
−
| blob0 auth hash
+
| blob0 ([[#Boot|Boot]]) auth hash
 
|-
 
|-
 
| 0x20
 
| 0x20
 
| 0x10
 
| 0x10
−
| blob1 auth hash
+
| blob1 ([[#KeygenLdr|KeygenLdr]]) auth hash
 
|-
 
|-
 
| 0x30
 
| 0x30
 
| 0x10
 
| 0x10
−
| blob2 auth hash
+
| blob2 ([[#Keygen|Keygen]]) auth hash
 
|-
 
|-
 
| 0x40
 
| 0x40
 
| 0x10
 
| 0x10
−
| blob2 AES IV
+
| blob2 ([[#Keygen|Keygen]]) AES IV
 
|-
 
|-
 
| 0x50
 
| 0x50
Line 1,540: Line 1,824:  
| 0x70
 
| 0x70
 
| 0x04
 
| 0x04
−
| blob0 size
+
| blob0 ([[#Boot|Boot]]) size
 
|-
 
|-
 
| 0x74
 
| 0x74
 
| 0x04
 
| 0x04
−
| blob1 size
+
| blob1 ([[#KeygenLdr|KeygenLdr]]) size
 
|-
 
|-
 
| 0x78
 
| 0x78
 
| 0x04
 
| 0x04
−
| blob2 size
+
| blob2 ([[#Keygen|Keygen]]) size
 +
|-
 +
| 0x7C
 +
| 0x04
 +
| [6.2.0+] blob3 ([[#Loader|Loader]]) size
 
|-
 
|-
 +
| 0x80
 +
| 0x04
 +
| [6.2.0+] blob4 ([[#Payload|Payload]]) size
 
|}
 
|}
    
== Notes ==
 
== Notes ==
−
   
[https://wiki.0x04.net/wiki/Marcin_Ko%C5%9Bcielnicki mwk] shared additional info learned from RE of falcon processors over the years, which hasn't made it into envytools documentation yet:
 
[https://wiki.0x04.net/wiki/Marcin_Ko%C5%9Bcielnicki mwk] shared additional info learned from RE of falcon processors over the years, which hasn't made it into envytools documentation yet:
    
=== cxset ===
 
=== cxset ===
−
   
cxset instruction provides a way to change behavior of a variable amount of successively executed DMA-related instructions.
 
cxset instruction provides a way to change behavior of a variable amount of successively executed DMA-related instructions.
   Line 1,567: Line 1,856:     
==== Override Types ====
 
==== Override Types ====
−
   
Unlisted values are unknown, but probably do something.
 
Unlisted values are unknown, but probably do something.
   Line 1,583: Line 1,871:     
==== DMA-Related Instructions ====
 
==== DMA-Related Instructions ====
−
   
At least the following instructions may have changed behavior, and count against the cxset "count" argument: <code>xdwait</code>, <code>xdst</code>, <code>xdld</code>.
 
At least the following instructions may have changed behavior, and count against the cxset "count" argument: <code>xdwait</code>, <code>xdst</code>, <code>xdld</code>.
   Line 1,589: Line 1,876:     
=== Register ACLs ===
 
=== Register ACLs ===
−
   
Falcon tracks permission metadata about each crypto reg. Permissions include read/write ability per execution mode, as well as ability to use the reg for encrypt/decrypt, among other permissions. Permissions are propagated when registers are referenced by instructions (e.g. moving a value from read-protected $cX to $cY will result in $cY also being read-protected).
 
Falcon tracks permission metadata about each crypto reg. Permissions include read/write ability per execution mode, as well as ability to use the reg for encrypt/decrypt, among other permissions. Permissions are propagated when registers are referenced by instructions (e.g. moving a value from read-protected $cX to $cY will result in $cY also being read-protected).
    
=== Authenticated Mode Entry/Exit ===
 
=== Authenticated Mode Entry/Exit ===
−
   
Entry to Authenticated Mode always sets $pc to the address supplied in $cauth (ie the base of the signature-checked region). This takes effect when trying to branch to any address within the range covered by $cauth. Entry to Authenticated Mode (also called "Secure Mode") computes a MAC over the $cauth region and compares it to $c6 in order to perform the signature check.
 
Entry to Authenticated Mode always sets $pc to the address supplied in $cauth (ie the base of the signature-checked region). This takes effect when trying to branch to any address within the range covered by $cauth. Entry to Authenticated Mode (also called "Secure Mode") computes a MAC over the $cauth region and compares it to $c6 in order to perform the signature check.
   Line 1,599: Line 1,884:     
=== Unknown Instructions ===
 
=== Unknown Instructions ===
−
   
<code>00000000: f5 3c XY e0    cchmod $cY $cX</code> - likely forces a change of permissions.
 
<code>00000000: f5 3c XY e0    cchmod $cY $cX</code> - likely forces a change of permissions.
  
Retrieved from "https://switchbrew.org/wiki/Special:MobileDiff/5575"