Changes between Version 56 and Version 57 of boot_procedure

Timestamp:

Mar 2, 2019, 4:31:55 PM (6 years ago)

Author:

alain

Comment:

--

boot_procedure

@@ -79 +79 @@
 The first instructions of the boot-loader are defined in the ''boot_entry.S'' file. This assembly code is executed by all cores entering the boot-loader, but not at the same time.
 
-Each core running this code makes the 3 following actions: 
+Each core running this assembly code makes the 3 following actions: 
    * It initializes the core stack pointer depending on the '''lid''' value extracted from the '''gid''', using the BOOT_STACK_BASE and BOOT_STACK_SIZE parameters defined in the  ''boot_config.h'' file,                                                                    
-   * It changes the value of the DATA address extension CP2 register, using the '''cxy''' value extracted from the '''gid'''                                                                            
+   * It changes the value of the DATA address extension CP2 register, using the '''cxy''' value extracted from the '''gid''', to force all cores to use the local stack segments.                                                                            
    * It jumps to the boot_loader() C function defined in the ''boot.c'' file, passing the two (cxy , lid) arguments.
 
 In this sequencial phase, the core[0][0]  executing this C function makes the following actions:
-   * The core[0][0] initializes 2 peripherals: The '''TTY''' terminal (channel 0)  to display log messages, and the '''IOC''' peripheral to access the disk.
+   * The core[0][0] initializes 2 peripherals: The '''TTY''' terminal (channel 0)  to display log messages, and the '''IOC''' peripheral to access the disk file system.
    * The core[0][0] initializes the boot-loader FAT32, allowing the boot loader to access files stored in the FAT32 file system on disk.
    * The core[0][0] load in the KERNEL_ELF zone the ''kernel.elf'' file from the disk file system..
-   * Then it copies in the KERNEL_CORE zone the ''kcode'' and ''data'' segments, using the addresses contained in the .elf file (identity mapping).
+   * Then it copies in the KERNEL_CORE zone the ''kcode'' and ''kdata'' segments, using the addresses contained in the .elf file (identity mapping).
    * The core[0][0] load in the ARCH_INFO zone the ''arch_info.bin'' file from the disk file system.
    * Then it builds from this ''arch_info.t'' structure the specific ''boot_info_t'' structure for cluster 0, and stores it in the ''kdata'' segment.
-   * The core[0][0] send IPIs to activate all cores [i][0] in all other clusters.
+   * The core[0][0] send IPIs to activate all cores [cxy][0] in all other clusters.
     
 === B3. Boot-loader partially parallel phase ===
@@ -99 +99 @@
 At this point, all DATA extension registers point already on the local cluster( to use the local stack).
 
-Therefore, the core[cxy][0] exécutes the following tasks:
+The core[cxy][0] exécute the following tasks:
     * To access the global data stored in cluster cxy, the core[cxy][0] copies the boot-loader code from BOOT_CODE zone in cluster 0 to BOOT_CORE zone in cluster cxy.
-    * To access the instructions stored in cluster cxy, the core[cxy][0] creates a minimal page table containing one single big page mapping the local BOOT_CORE zone, and activates the instruction MMU. '''[TO BE DONE]'''
+    * To access the instructions stored in cluster cxy, the core[cxy][0] creates a minimal page table containing two big pages mapping respectively the local BOOT_CORE zone, and the local KERNEL_CODE zone, and activates the instruction MMU. '''[TO BE DONE]'''
     * The core[cxy][0] copies the ''arch_info.bin'' structure from ARCH_INFO zone in cluster 0 to ARCH_INFO zone in cluster cxy.
     * The core[cxy][0] copies the ''kcode'' and ''kdata'' segments from KERNEL_CODE zone in cluster 0 to KERNEL_CODE zone in cluster cxy. 
     * The core[cxy][0] builds from the ''arch_info.t'' the specific ''boot_info_t'' structure for cluster cxy, and stores it in the local ''kdata'' segment.
-    *  All core[cxy][0], including core[0][0], synchronize using a global barrier.
-    * in each cluster cxy, the core[cxy][0] activates the other cores that are  blocked in the pre-loader.
+    * All core[cxy][0], including core[0][0], synchronize using a global barrier.
+    * In each cluster cxy, the core[cxy][0] activates the other cores that are  blocked in the pre-loader.
 
 === B4. Boot-loader fully parallel phase ===