Properly configure chassis power LED GPIO at startup

Avoid interference between 7 segment display and power LED

kestrel/src/kestrel.c

@@ -342,6 +342,7 @@ static void reboot(void)
 
 static void display_character(char character, int dp)
 {
+    uint32_t dword;
     uint16_t value;
 
     // FIXME Only supports numbers for now
@@ -382,7 +383,10 @@ static void display_character(char character, int dp)
             break; // OFF
     }
 
-    gpio3_out_write(~(value | ((dp == 0) ? 0x0000 : 0x4000)));
+    dword = gpio3_out_read();
+    dword &= ~0x7fff;
+    dword |= (~(value | ((dp == 0) ? 0x0000 : 0x4000))) & 0x7fff;
+    gpio3_out_write(dword);
 }
 
 static void host_power_status_changed(void)
@@ -402,7 +406,7 @@ static void host_power_status_changed(void)
     // Write power LED status to GPIO register
     dword = gpio3_out_read();
     dword &= ~(0x1 << 15);
-    dword |= (power_led_on & 0x1) << 15;
+    dword |= (~(power_led_on & 0x1) << 15) & 0x8000;
     gpio3_out_write(dword);
 }
 
@@ -471,9 +475,9 @@ static void gpio_init(void)
     set_led_bank_display(0x00);
     gpio1_oe_write(0xff);
 
-    // Set up alphanumeric display
-    gpio3_out_write(0xefff);
-    gpio3_oe_write(0xefff);
+    // Set up alphanumeric display / power LED
+    gpio3_out_write(0xffff);
+    gpio3_oe_write(0xffff);
 }
 
 static void set_lpc_slave_irq_enable(uint8_t enabled)