2022-10-23 23:45:43 -07:00

350 lines
11 KiB
C

//*****************************************************************************
//
// am_hal_otp.c
//! @file
//!
//! @brief Functions for handling the OTP interface.
//
//*****************************************************************************
//*****************************************************************************
//
// Copyright (c) 2020, Ambiq Micro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
// Third party software included in this distribution is subject to the
// additional license terms as defined in the /docs/licenses directory.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// This is part of revision 2.4.2 of the AmbiqSuite Development Package.
//
//*****************************************************************************
#include "am_mcu_apollo.h"
#include "am_hal_flash.h"
//*****************************************************************************
//
//! @brief Check if debugger is currently locked out.
//!
//! @param None.
//!
//! Determine if the debugger is already locked out.
//!
//! @return non-zero if debugger is currently locked out.
//! Specifically:
//! 0 = debugger is not locked out.
//! 1 = debugger is locked out.
//
//*****************************************************************************
int
am_hal_otp_is_debugger_lockedout(void)
{
uint32_t u32Val, uBF;
//
// Get current value of the debugger port word
//
u32Val = am_hal_flash_load_ui32(AM_HAL_OTP_DBGRPROT_ADDR);
//
// Check if already locked out.
//
uBF = AM_READ_SM(AM_OTP_DBGR_LOCKOUT, u32Val);
switch ( uBF )
{
case 0xF:
return 0;
case 0xA:
return 1;
default:
return 1;
}
}
//*****************************************************************************
//
//! @brief Lock out debugger access.
//!
//! @param None.
//!
//! This function locks out access by a debugger.
//!
//! @return 0 if lockout was successful or if lockout was already enabled.
//! Low byte=0xff, byte 1 contains current value of lockout.
//! Else, return value from HAL programming function.
//
//*****************************************************************************
int
am_hal_otp_debugger_lockout(void)
{
uint32_t u32Val;
int iRet;
iRet = am_hal_otp_is_debugger_lockedout();
if ( iRet == 1 )
{
return 0;
}
else if ( iRet != 0 )
{
//
// Uh-oh, something's weird.
// We're locked out but not in the expected way.
// Return as an error with the current (non-0xF) value encoded in
// byte 1.
//
return (iRet << 8) | 0xff;
}
u32Val = am_hal_flash_load_ui32(AM_HAL_OTP_DBGRPROT_ADDR);
//
// Modify the appropriate bitfield for debugger lockout.
//
u32Val &= ~AM_OTP_DBGR_LOCKOUT_M;
u32Val |= AM_WRITE_SM(AM_OTP_DBGR_LOCKOUT, 0xA);
iRet = am_hal_flash_program_otp(AM_HAL_FLASH_OTP_KEY,
0,
&u32Val,
AM_HAL_OTP_DBGR_O / 4,
1);
return iRet;
}
//*****************************************************************************
//
//! @brief Lock out SRAM access.
//!
//! @param None.
//!
//! This function locks out access by a debugger to SRAM.
//!
//! @return 0 if lockout was successful or if lockout was already enabled.
//! Low byte=0xff, byte 1 contains current value of lockout.
//! Else, return value from HAL programming function.
//
//*****************************************************************************
int
am_hal_otp_sram_lockout(void)
{
uint32_t u32Val;
int iRet;
//
// Get current value of the debugger port word
//
u32Val = am_hal_flash_load_ui32(AM_HAL_OTP_DBGRPROT_ADDR);
//
// Check if SRAM already locked out.
//
if ( AM_READ_SM(AM_OTP_SRAM_LOCKOUT, u32Val) == 0xA )
{
//
// Already done, return with no error.
//
return 0;
}
//
// Check for invalid value (which is effectively already locked out).
//
if ( AM_READ_SM(AM_OTP_SRAM_LOCKOUT, u32Val) != 0xF )
{
//
// Uh-oh, something's wrong.
// Return as an error with the current (non-0xF) value encoded in
// byte 1.
//
return (AM_READ_SM(AM_OTP_SRAM_LOCKOUT, u32Val) << 8) | 0xff;
}
//
// Modify the appropriate bitfield for SRAM access lockout.
//
u32Val &= ~AM_OTP_SRAM_LOCKOUT_M;
u32Val |= AM_WRITE_SM(AM_OTP_SRAM_LOCKOUT, 0xA);
iRet = am_hal_flash_program_otp(AM_HAL_FLASH_OTP_KEY,
0,
&u32Val,
AM_HAL_OTP_DBGR_O / 4,
1);
return iRet;
}
//*****************************************************************************
//
//! @brief Set copy (read) protection.
//!
//! @param @u32BegAddr The beginning address to be copy protected.
//! @u32EndAddr The ending address to be copy protected.
//!
//! @note For Apollo, the u32BegAddr parameter should be on a 16KB boundary, and
//! the u32EndAddr parameter should be on a (16KB-1) boundary. Otherwise
//! both parameters will be truncated/expanded to do so.
//! For example, if u32BegAddr=0x1000 and u32EndAddr=0xC200, the actual
//! range that protected is: 0x0 - 0xFFFF.
//!
//! This function enables copy protection on a given flash address range.
//!
//! @return 0 if copy protection was successfully enabled.
//
//*****************************************************************************
int
am_hal_otp_set_copy_protection(uint32_t u32BegAddr, uint32_t u32EndAddr)
{
int iRet;
uint32_t u32BfMask, u32Val;
//
// Validate the parameters.
//
if ( (u32BegAddr > u32EndAddr) ||
(u32EndAddr > (AM_HAL_FLASH_ADDR + AM_HAL_FLASH_TOTAL_SIZE - 1)) )
{
//
// Invalid arguments.
//
return 1;
}
//
// Force given addresses to appropriate boundaries.
//
u32BegAddr &= ~(AM_HAL_OTP_CHUNKSIZE-1);
u32EndAddr |= (AM_HAL_OTP_CHUNKSIZE-1);
//
// Create the bitmask for the protection word.
//
u32BfMask = AM_HAL_OTP_PROT_M(u32BegAddr, u32EndAddr);
//
// Now, set the mask in the copy-protection OTP.
//
iRet = am_hal_flash_program_otp(AM_HAL_FLASH_OTP_KEY,
0,
&u32BfMask,
AM_HAL_OTP_COPYPROT_O / 4,
1);
//
// Now, read it back and make sure we cleared the bits we intended to clear.
//
u32Val = am_hal_flash_load_ui32(AM_HAL_OTP_COPYPROT_ADDR);
if ( (u32Val & u32BfMask) != u32BfMask )
{
//
// Something went awry. Not all the intended bits were set to 0
// during the programming cycle. Return an error.
//
iRet = 0xff;
}
return iRet;
}
//*****************************************************************************
//
//! @brief Set write protection.
//!
//! @param @u32BegAddr The beginning address to be write protected.
//! @u32EndAddr The ending address to be write protected.
//!
//! @note For Apollo, the u32BegAddr parameter should be on a 16KB boundary, and
//! the u32EndAddr parameter should be on a (16KB-1) boundary. Otherwise
//! both parameters will be truncated/expanded to do so.
//! For example, if u32BegAddr=0x1000 and u32EndAddr=0xC200, the actual
//! range that protected is: 0x0 - 0xFFFF.
//!
//! This function enables write protection on a given flash address range.
//!
//! @return 0 if write protection was successfully enabled.
//
//*****************************************************************************
int
am_hal_otp_set_write_protection(uint32_t u32BegAddr, uint32_t u32EndAddr)
{
int iRet;
uint32_t u32BfMask, u32Val;
//
// Validate the parameters.
//
if ( (u32BegAddr > u32EndAddr) ||
(u32EndAddr > (AM_HAL_FLASH_ADDR + AM_HAL_FLASH_TOTAL_SIZE - 1)) )
{
//
// Invalid arguments.
//
return 1;
}
//
// Force given addresses to appropriate boundaries.
//
u32BegAddr &= ~(AM_HAL_OTP_CHUNKSIZE-1);
u32EndAddr |= (AM_HAL_OTP_CHUNKSIZE-1);
//
// Create the bitmask for the protection word.
//
u32BfMask = AM_HAL_OTP_PROT_M(u32BegAddr, u32EndAddr);
//
// Now, set the mask in the write-protection OTP.
//
iRet = am_hal_flash_program_otp(AM_HAL_FLASH_OTP_KEY,
0,
&u32BfMask,
AM_HAL_OTP_WRITPROT_O / 4,
1);
//
// Now, read it back and make sure we cleared the bits we intended to clear.
//
u32Val = am_hal_flash_load_ui32(AM_HAL_OTP_WRITPROT_ADDR);
if ( (u32Val & u32BfMask) != u32BfMask )
{
//
// Something went awry. Not all the intended bits were set to 0
// during the programming cycle. Return an error.
//
iRet = 0xff;
}
return iRet;
}
//*****************************************************************************
//
// End Doxygen group.
//! @}
//
//*****************************************************************************