Add initial center firmware

1 files changed, 103 insertions, 0 deletions

diff --git a/fw/main.c b/fw/main.c
new file mode 100644
index 0000000..b599cff
--- /dev/null
+++ b/fw/main.c
@@ -0,0 +1,103 @@
+/* Megumin LED display firmware
+ * Copyright (C) 2018 Sebastian Götte <code@jaseg.net>
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "global.h"
+
+volatile unsigned int sys_time = 0;
+volatile unsigned int sys_time_seconds = 0;
+
+int main(void) {
+    RCC->CR |= RCC_CR_HSEON;
+    while (!(RCC->CR&RCC_CR_HSERDY));
+    RCC->CFGR &= ~RCC_CFGR_PLLMUL_Msk & ~RCC_CFGR_SW_Msk & ~RCC_CFGR_PPRE_Msk & ~RCC_CFGR_HPRE_Msk;
+    RCC->CFGR |= (2<<RCC_CFGR_PLLMUL_Pos) | RCC_CFGR_PLLSRC_HSE_PREDIV; /* PLL x4 -> 32.0MHz */
+    RCC->CFGR2 &= ~RCC_CFGR2_PREDIV_Msk;
+    RCC->CFGR2 |= RCC_CFGR2_PREDIV_DIV2; /* prediv :2 -> 4.0MHz */
+    RCC->CR |= RCC_CR_PLLON;
+    while (!(RCC->CR&RCC_CR_PLLRDY));
+    RCC->CFGR |= (2<<RCC_CFGR_SW_Pos);
+    SystemCoreClockUpdate();
+
+    /* Turn on lots of neat things */
+    RCC->AHBENR  |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_FLITFEN;
+    RCC->APB2ENR |= RCC_APB2ENR_SYSCFGEN | RCC_APB2ENR_DBGMCUEN | RCC_APB2ENR_TIM1EN;
+    RCC->APB1ENR |= RCC_APB1ENR_TIM3EN;
+
+    GPIOA->MODER |=
+          (3<<GPIO_MODER_MODER0_Pos)  /* PA0  - Vmeas_A */
+        | (3<<GPIO_MODER_MODER1_Pos)  /* PA1  - Vmeas_B */
+        | (1<<GPIO_MODER_MODER2_Pos)  /* PA2  - LOAD */
+        | (1<<GPIO_MODER_MODER3_Pos)  /* PA3  - CH0 */
+        | (1<<GPIO_MODER_MODER4_Pos)  /* PA4  - CH3 */
+        | (0<<GPIO_MODER_MODER5_Pos)  /* PA5  - TP1 */
+        | (1<<GPIO_MODER_MODER6_Pos)  /* PA6  - CH2 */
+        | (1<<GPIO_MODER_MODER7_Pos)  /* PA7  - CH1 */
+        | (0<<GPIO_MODER_MODER9_Pos)  /* PA9  - TP2 */
+        | (0<<GPIO_MODER_MODER10_Pos);/* PA10 - TP3 */
+
+    /* Set shift register IO GPIO output speed */
+    GPIOA->OSPEEDR |=
+          (2<<GPIO_OSPEEDR_OSPEEDR2_Pos)   /* LOAD */
+        | (2<<GPIO_OSPEEDR_OSPEEDR3_Pos)   /* CH0 */
+        | (2<<GPIO_OSPEEDR_OSPEEDR4_Pos)   /* CH3   */
+        | (2<<GPIO_OSPEEDR_OSPEEDR6_Pos)   /* CH2 */
+        | (2<<GPIO_OSPEEDR_OSPEEDR7_Pos);  /* CH1 */
+
+    SysTick_Config(SystemCoreClock/1000); /* 1ms interval */
+
+    void set_outputs(uint8_t val) {
+        int a=!!(val&1), b=!!(val&2), c=!!(val&4), d=!!(val&8);
+        GPIOA->ODR &= ~(!a<<3 | !b<<7 | c<<6 | d<<4);
+        GPIOA->ODR |= a<<3 | b<<7 | !c<<6 | !d<<4;
+    }
+    while (42) {
+#define FOO 500000
+        for (int i=0; i<FOO; i++) ;
+        set_outputs(0x1);
+        for (int i=0; i<FOO; i++) ;
+        set_outputs(0x2);
+        for (int i=0; i<FOO; i++) ;
+        set_outputs(0x4);
+        for (int i=0; i<FOO; i++) ;
+        set_outputs(0x8);
+    }
+}
+
+void NMI_Handler(void) {
+}
+
+void HardFault_Handler(void) __attribute__((naked));
+void HardFault_Handler() {
+    asm volatile ("bkpt");
+}
+
+void SVC_Handler(void) {
+}
+
+
+void PendSV_Handler(void) {
+}
+
+void SysTick_Handler(void) {
+    static int n = 0;
+    sys_time++;
+    if (n++ == 1000) {
+        n = 0;
+        sys_time_seconds++;
+    }
+}
+