diff options
| -rw-r--r-- | stmhal/boards/LIMIFROG/board_init.c | 154 | ||||
| -rw-r--r-- | stmhal/boards/LIMIFROG/mpconfigboard.h | 3 |
2 files changed, 157 insertions, 0 deletions
diff --git a/stmhal/boards/LIMIFROG/board_init.c b/stmhal/boards/LIMIFROG/board_init.c new file mode 100644 index 0000000000..72f9208424 --- /dev/null +++ b/stmhal/boards/LIMIFROG/board_init.c @@ -0,0 +1,154 @@ +// The code is this file allows the user to enter DFU mode when the board +// starts up, by connecting POS10 on the external connector to GND. +// The code itself is taken from the LimiFrog software repository found at +// https://github.com/LimiFrog/LimiFrog-SW, and the original license header +// is copied below. + +#include STM32_HAL_H + +static void LBF_DFU_If_Needed(void); + +void LIMIFROG_board_early_init(void) { + LBF_DFU_If_Needed(); +} + +/******************************************************************************* + * LBF_DFU_If_Needed.c + * + * (c)2015 LimiFrog / CYMEYA + * This program is licensed under the terms of the MIT License. + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND. + * Please refer to the License File LICENSE.txt located at the root of this + * project for full licensing conditions, + * or visit https://opensource.org/licenses/MIT. + ******************************************************************************/ + +#define __LIMIFROG_02 + +/* ==== BTLE (excl UART) ======================================== */ +// PC9 = BT_RST (active high) + +#define BT_RST_PIN GPIO_PIN_9 +#define BT_RST_PORT GPIOC + +// Position 10 +#ifdef __LIMIFROG_01 + #define CONN_POS10_PIN GPIO_PIN_9 + #define CONN_POS10_PORT GPIOB +#else + #define CONN_POS10_PIN GPIO_PIN_8 + #define CONN_POS10_PORT GPIOB +#endif + +static inline void GPIO_HIGH(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin) +{ + GPIOx->BSRR = (uint32_t)GPIO_Pin; +} + +static inline int IS_GPIO_RESET(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin) +{ + GPIO_PinState bitstatus; + if((GPIOx->IDR & GPIO_Pin) != (uint32_t)GPIO_PIN_RESET) + { + bitstatus = GPIO_PIN_SET; + } + else + { + bitstatus = GPIO_PIN_RESET; + } + return (bitstatus==GPIO_PIN_RESET); +} + +/************************************************************** + RATIONALE FOR THIS FUNCTION : + + - The STM32 embeds in ROM a bootloader that allows to + obtain code and boot from a number of different interfaces, + including USB in a mode called "DFU" (Device Frimware Update) + [see AN3606 from ST for full details] + This bootloader code is executed instead of the regular + application code when pin BOOT0 is pulled-up (which on + LimiFrog0.2 is achieved by pressing the general-purpose + pushbutton switch on the side. + - The bootloader monitors a number of IOs of the STM32 to decide + from which interface it should boot. + - Problem in LimiFrog (up to versions 0.2a at least): upon + power-up the BLE modules generates some activity on UART3, + which is part of the pins monitored by the STM32. + This misleads the bootloader in trying to boot from UART3 + and, as a result, not continuing with booting from USB. + + - This code implements an alternative solution to launch the + bootloader while making sure UART3 remains stable. + - The idea it to start application code with a check, prior to any + other applicative code, of whether USB bootload is required (as + flagged by a GPIO pulled low at reset, in the same way as BOOT0). + The hadware reset pin of BLE is asserted (so that now it won't + generate any acitivity on UART3), and if USB bootload is required : + bootload ROM is remapped at address 0x0, stack pointer is + updated and the code is branched to the start of the bootloader. + - This code is run prior to any applicative configuration of clocks, + IRQs etc. -- the STM32 is therefore still running from MSI + + THIS FUNCTION MAY BE SUPPRESSED IF YOU NEVER NEED TO BOOT DFU MODE + + ********************************************************************/ + +static void LBF_DFU_If_Needed(void) +{ + + + GPIO_InitTypeDef GPIO_InitStruct; + + + // Initialize and assert pin BTLE_RST + // (hw reset to BLE module, so it won't drive UART3) + + __GPIOC_CLK_ENABLE(); + GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP; + GPIO_InitStruct.Pull = GPIO_NOPULL; + GPIO_InitStruct.Speed = GPIO_SPEED_LOW; + GPIO_InitStruct.Pin = BT_RST_PIN; + HAL_GPIO_Init(BT_RST_PORT, &GPIO_InitStruct); + + GPIO_HIGH(BT_RST_PORT, BT_RST_PIN); // assert BTLE reset + + + /* -- Bootloader will be called if position 10 on the extension port + is actively pulled low -- */ + // Note - this is an arbitrary choice, code could be modified to + // monitor another GPIO of the STM32 and/or decide that active level + // is high rather than low + + + // Initialize Extension Port Position 10 = PB8 (bears I2C1_SCL) + // Use weak pull-up to detect if pin is externally pulled low + + __GPIOB_CLK_ENABLE(); + GPIO_InitStruct.Mode = GPIO_MODE_INPUT; + GPIO_InitStruct.Pull = GPIO_PULLUP; + GPIO_InitStruct.Pin = CONN_POS10_PIN; + HAL_GPIO_Init(CONN_POS10_PORT, &GPIO_InitStruct); + + // If selection pin pulled low... + if ( IS_GPIO_RESET(CONN_POS10_PORT, CONN_POS10_PIN )) + + { + // Remap bootloader ROM (ie System Flash) to address 0x0 + SYSCFG->MEMRMP = 0x00000001; + + // Init stack pointer with value residing at ROM base + asm ( + "LDR R0, =0x00000000\n\t" // load ROM base address" + "LDR SP,[R0, #0]\n\t" // assign main stack pointer" + ); + + // Jump to address pointed by 0x00000004 -- */ + + asm ( + "LDR R0,[R0, #4]\n\t" // load bootloader address + "BX R0\n\t" + ); + + } +} diff --git a/stmhal/boards/LIMIFROG/mpconfigboard.h b/stmhal/boards/LIMIFROG/mpconfigboard.h index 8456e03513..782c9c90f8 100644 --- a/stmhal/boards/LIMIFROG/mpconfigboard.h +++ b/stmhal/boards/LIMIFROG/mpconfigboard.h @@ -16,6 +16,9 @@ #define MICROPY_HW_ENABLE_DAC (0) #define MICROPY_HW_ENABLE_CAN (0) +#define MICROPY_BOARD_EARLY_INIT LIMIFROG_board_early_init +void LIMIFROG_board_early_init(void); + // MSI is used and is 4MHz #define MICROPY_HW_CLK_PLLM (1) #define MICROPY_HW_CLK_PLLN (40) |