small system SRAM info output

[cortex-from-scratch] / sysinfo.c

diff --git a/sysinfo.c b/sysinfo.c
index 3971d3b..2d6f047 100644 (file)
--- a/sysinfo.c
+++ b/sysinfo.c
@@ -4,24 +4,25 @@
 #include <stm32.h>
 #include <mmap.h>
 
+#define MEM_SIZE       0x00010000 
+#define MEM_OFFSET     0x20000000
+
+uint32_t get_msp(void);
 
 void sysinfo() {
 
        uint32_t tmp = *MCU_ID;
-
-       uart_puts("CHECKING SYS INFO\n");
+       uart_puts("# ROBSYS 0.1 LOADING...\n");
        uart_puts("# DEVICE ID: ");
 
-       if (tmp & 0x414) {
+       if (tmp & 0x414) 
                uart_puts("HIGH DENSITY\n");
-       }
        else {
                uart_puts("UNKNOWN\n");
        }
 
        tmp = (tmp >> 16);
        uart_puts("# REVISION: ");
-//     addrtohex(tmp);
        switch  (tmp) {
                case 0x1000:
                      uart_puts("REVISION A\n");
@@ -36,5 +37,35 @@ void sysinfo() {
                      uart_puts("UNKNOWN\n");
        }
 
+       extern char _endofbss;
+       
+       uint32_t current_stack = get_msp();
+       uint32_t stack_usage = (MEM_OFFSET + MEM_SIZE) - current_stack;
+       uint32_t data_bss = &_endofbss - MEM_OFFSET;
+       uint32_t mem_free = MEM_SIZE - stack_usage - data_bss;
+
+       uart_puts("# TOTAL MEMORY: ");
+       addrtohex(MEM_SIZE);
+       uart_putc('\n');
+       uart_puts("# FREE MEMORY: ");
+       addrtohex(mem_free);
+       uart_putc('\n');
+       uart_puts("# STACK USAGE: ");
+       addrtohex(stack_usage);
+       uart_putc('\n');
+
 }
 
+/* Get the master stack pointer's position
+ * Here we use a so-called naked function, 
+ * that doesn't automatically push and pop  */
+
+uint32_t get_msp(void) __attribute__( ( naked ) );
+uint32_t get_msp(void)
+{
+  uint32_t msp = 0;
+  __asm__ volatile ("mrs %0, msp\n\t" 
+                  "mov r0, %0 \n\t"
+                  "bx lr     \n\t"  : "=r" (msp) );
+  return(msp);
+}