Remove debug prints, and add USE_USB_DPRAM option

Author: will-v-pi

enc_bootloader/CMakeLists.txt

@@ -38,10 +38,19 @@ if (NOT USE_PRECOMPILED)
         pico_rand
     )
 
+    # use stack guards, as AES variables are written near the stack
+    target_compile_definitions(enc_bootloader PRIVATE PICO_USE_STACK_GUARDS=1)
+
     pico_set_binary_type(enc_bootloader no_flash)
+    set(USE_USB_DPRAM FALSE)
     # create linker script to run from 0x20070000
     file(READ ${PICO_LINKER_SCRIPT_PATH}/memmap_no_flash.ld LINKER_SCRIPT)
-    string(REPLACE "RAM(rwx) : ORIGIN =  0x20000000, LENGTH = 512k" "RAM(rwx) : ORIGIN =  0x20078000, LENGTH = 32k" LINKER_SCRIPT "${LINKER_SCRIPT}")
+    if (USE_USB_DPRAM)
+        string(REPLACE "RAM(rwx) : ORIGIN =  0x20000000, LENGTH = 512k" "RAM(rwx) : ORIGIN =  0x2007D000, LENGTH = 12k" LINKER_SCRIPT "${LINKER_SCRIPT}")
+        target_compile_definitions(enc_bootloader PRIVATE USE_USB_DPRAM=1)
+    else()
+        string(REPLACE "RAM(rwx) : ORIGIN =  0x20000000, LENGTH = 512k" "RAM(rwx) : ORIGIN =  0x2007C000, LENGTH = 16k" LINKER_SCRIPT "${LINKER_SCRIPT}")
+    endif()
     file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/memmap_enc_bootloader.ld "${LINKER_SCRIPT}")
     pico_set_linker_script(enc_bootloader ${CMAKE_CURRENT_BINARY_DIR}/memmap_enc_bootloader.ld)
 else()

enc_bootloader/enc_bootloader.c

@@ -3,16 +3,19 @@
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
+
+#ifdef DEBUG_PRINT
 #include <stdio.h>
+#endif
 #include <string.h>
 #include "pico/stdlib.h"
 #include "boot/picobin.h"
-#include "hardware/uart.h"
 #include "pico/bootrom.h"
 #include "pico/rand.h"
 #include "hardware/structs/otp.h"
-#include "hardware/structs/qmi.h"
-#include "hardware/structs/xip_ctrl.h"
+#if USE_USB_DPRAM
+#include "hardware/structs/usb_dpram.h"
+#endif
 
 #include "pico/binary_info.h"
 
@@ -63,14 +66,20 @@ static void init_aes() {
     init_lut_map();
 }
 
+#if USE_USB_DPRAM
+uint8_t* workarea = (uint8_t*)USBCTRL_DPRAM_BASE;
+#else
 static __attribute__((aligned(4))) uint8_t workarea[4 * 1024];
+#endif
 
 int main() {
+#ifdef DEBUG_PRINT
     stdio_init_all();
 
     printf("Decrypting the image\n");
     printf("OTP Valid Keys %x\n", otp_hw->key_valid);
     printf("Unlocking\n");
+#endif
     for (int i=0; i<4; i++) {
         uint32_t key_i = ((i*2+1) << 24) | ((i*2+1) << 16) |
                          (i*2 << 8) | i*2;
@@ -93,9 +102,11 @@ int main() {
     memcpy(iv + 8, (void*)&iv2, sizeof(iv2));
     memcpy(iv + 12, (void*)&iv3, sizeof(iv3));
 
+#ifdef DEBUG_PRINT
     printf("Pre decryption image begins with\n");
     for (int i=0; i < 4; i++)
         printf("%08x\n", *(uint32_t*)(data_start_addr + i*4));
+#endif
 
     init_aes();
     // Read key directly from OTP - guarded reads will throw a bus fault if there are any errors
@@ -105,23 +116,27 @@ int main() {
     otp_hw->sw_lock[otp_key_page] = 0xf;
     ctr_crypt_s(iv, (void*)data_start_addr, data_size/16);
 
+#ifdef DEBUG_PRINT
     printf("Post decryption image begins with\n");
     for (int i=0; i < 4; i++)
         printf("%08x\n", *(uint32_t*)(data_start_addr + i*4));
 
     printf("Chaining into %x, size %x\n", data_start_addr, data_size);
 
     stdio_deinit_all();
+#endif
 
     int rc = rom_chain_image(
         workarea,
-        sizeof(workarea),
+        4 * 1024,
         data_start_addr,
         data_size
     );
 
+#ifdef DEBUG_PRINT
     stdio_init_all();
     printf("Shouldn't return from ROM call %d\n", rc);
+#endif
 
     reset_usb_boot(0, 0);
 }

enc_bootloader/enc_bootloader.elf

@@ -4940,7 +4940,6 @@ bool encrypt_command::execute(device_map &devices) {
             // Bootloader size
             auto bootloader_txt = enc_elf->get_section(".text");
             uint32_t bootloader_size = 0x20082000 - bootloader_txt->virtual_address();
-            printf("Bootloader size %08x start %08x\n", bootloader_size, bootloader_txt->virtual_address());
 
             // Move bootloader down in physical space to start of SRAM (which will be start of flash once packaged)
             enc_elf->move_all(data_start_address - bootloader_txt->virtual_address());