fix(linker): add data no copy section for boot related vars

Signed-off-by: Daniel Oliveira <[email protected]>

Author: danielRep

src/arch/armv8/aarch32/boot.S

@@ -16,7 +16,7 @@
     add \rd, \rd, r1
 .endm
 
-.data
+.section .datanocopy
 .balign 4
 /**
  * barrier is used to minimal synchronization in boot - other cores wait for bsp to set it.
@@ -108,7 +108,7 @@ _reset_handler:
  * which later will turn on all the others. Therefore, there is no concurrency when setting
  * CPU_MASTER and no atomic operations are needed.
  */
- .pushsection .data
+ .pushsection .datanocopy
 _master_set:
     .4byte 0
 .popsection

src/arch/armv8/cpu.c

@@ -8,7 +8,7 @@
 #include <platform.h>
 #include <arch/sysregs.h>
 
-cpuid_t CPU_MASTER __attribute__((section(".data")));
+cpuid_t CPU_MASTER __attribute__((section(".datanocopy")));
 
 /* Perform architecture dependent cpu cores initializations */
 void cpu_arch_init(cpuid_t cpuid, paddr_t load_addr)

src/arch/riscv/cpu.c

@@ -8,7 +8,7 @@
 #include <arch/sbi.h>
 #include <platform.h>
 
-cpuid_t CPU_MASTER __attribute__((section(".data")));
+cpuid_t CPU_MASTER __attribute__((section(".datanocopy")));
 
 /* Perform architecture dependent cpu cores initializations */
 void cpu_arch_init(cpuid_t cpuid, paddr_t load_addr)

src/core/mem.c

@@ -20,9 +20,9 @@ extern uint8_t _image_start, _image_load_end, _image_end, _vm_image_start, _vm_i
 struct list page_pool_list;
 
 /* The address where the Bao image is loaded in memory */
-vaddr_t img_addr __attribute__((section(".data")));
+vaddr_t img_addr __attribute__((section(".datanocopy")));
 /* The address where the data section is loaded in memory */
-vaddr_t data_addr __attribute__((section(".data")));
+vaddr_t data_addr __attribute__((section(".datanocopy")));
 
 static bool pp_bitmap_alloc(size_t pool_num_pages, bitmap_t** bitmap)
 {

src/linker.ld

@@ -56,22 +56,25 @@ SECTIONS
         _ipi_cpumsg_handlers_id_end = .;
 	}
 
-	.pad_load : {
+    _image_load_end = .;
+
+	.datanocopy : ALIGN(PAGE_SIZE) {
+		/**
+		 * This section holds data initialized and used during early stages of the boot that can't
+		 * be later rewritten during the copy of data sections from non-volatile memory
+		 */
+		*(.datanocopy)
 		/**
-		 * This section ensures the loadable portion of the image (_image_load_end) is page-aligned
-		 * by adding padding if necessary. The BYTE(0x00) forces this section to be PROGBITS rather
-		 * than NOBITS, ensuring any padding bytes are actually written to the file up to the align
+		 * Ensure the loadable portion of the image (_image_load_end) is page-aligned by adding
+		 * padding if necessary.
 		 */
-		BYTE(0x00)
-		. = ALIGN(PAGE_SIZE);
+	    . = ALIGN(PAGE_SIZE);
 	}
 
-    _image_load_end = .;
-
 #ifdef MEM_NON_UNIFIED
 	/* Save the current location counter (VMA) and switch to LMA for .vm_images */
 	_vma_before_vm_images = .;
-    _image_load_end = _data_lma_start + (_image_load_end - _data_vma_start);
+    _image_load_end = ALIGN((_data_lma_start + (_image_load_end - _data_vma_start)), PAGE_SIZE);
 	. = _image_load_end;
 #endif