components/bootloader: fix enabling cache for APP CPU

This is a workaround for a hardware bug with cache initialization.
Only two lines of code related to DPORT_APP_CACHE_MMU_IA_CLR were added around mmu_init(1); call,
and two lines at the end of comment block.
I reformatted surrounding lines to use spaces for indentation, like the rest of the code in this file does.

diff --git a/components/bootloader/src/main/bootloader_start.c b/components/bootloader/src/main/bootloader_start.c
index 5c2a1868121bc5a67039c676ce0317f2a4f0bbf8..b9df64012a2e727425e4a506e477efd90cb17bd7 100644 (file)
--- a/components/bootloader/src/main/bootloader_start.c
+++ b/components/bootloader/src/main/bootloader_start.c
@@ -92,23 +92,28 @@ void IRAM_ATTR call_start_cpu0()
     //Clear bss
     memset(&_bss_start, 0, (&_bss_end - &_bss_start) * sizeof(_bss_start));
 
-       /* completely reset MMU for both CPUs
-          (in case serial bootloader was running) */
-       Cache_Read_Disable(0);
-       Cache_Read_Disable(1);
-       Cache_Flush(0);
-       Cache_Flush(1);
-       mmu_init(0);
-       mmu_init(1);
-       /* (above steps probably unnecessary for most serial bootloader
-          usage, all that's absolutely needed is that we unmask DROM0
-          cache on the following two lines - normal ROM boot exits with
-          DROM0 cache unmasked, but serial bootloader exits with it
-          masked. However can't hurt to be thorough and reset
-          everything.)
-       */
-       REG_CLR_BIT(PRO_CACHE_CTRL1_REG, DPORT_PRO_CACHE_MASK_DROM0);
-       REG_CLR_BIT(APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MASK_DROM0);
+    /* completely reset MMU for both CPUs
+       (in case serial bootloader was running) */
+    Cache_Read_Disable(0);
+    Cache_Read_Disable(1);
+    Cache_Flush(0);
+    Cache_Flush(1);
+    mmu_init(0);
+    REG_SET_BIT(APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MMU_IA_CLR);
+    mmu_init(1);
+    REG_CLR_BIT(APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MMU_IA_CLR);
+    /* (above steps probably unnecessary for most serial bootloader
+       usage, all that's absolutely needed is that we unmask DROM0
+       cache on the following two lines - normal ROM boot exits with
+       DROM0 cache unmasked, but serial bootloader exits with it
+       masked. However can't hurt to be thorough and reset
+       everything.)
+
+       The lines which manipulate DPORT_APP_CACHE_MMU_IA_CLR bit are
+       necessary to work around a hardware bug.
+    */
+    REG_CLR_BIT(PRO_CACHE_CTRL1_REG, DPORT_PRO_CACHE_MASK_DROM0);
+    REG_CLR_BIT(APP_CACHE_CTRL1_REG, DPORT_APP_CACHE_MASK_DROM0);
 
     bootloader_main();
 }