elfloader: use helper struct for DTB loading

Signed-off-by: Axel Heider <[email protected]>

elfloader-tool/include/elfloader_common.h

@@ -34,6 +34,15 @@ typedef uintptr_t vaddr_t;
 #define ARRAY_SIZE(a)       (sizeof(a)/sizeof((a)[0]))
 #define NULL                ((void *)0)
 
+
+/*
+ * Information about a DTB we are loading.
+ */
+typedef struct {
+    paddr_t phys_base;
+    size_t size;
+} dtb_info_t;
+
 /*
  * Information about an image we are loading.
  */
@@ -93,9 +102,7 @@ int load_images(
     struct image_info *user_info,
     unsigned int max_user_images,
     unsigned int *num_images,
-    void const *bootloader_dtb,
-    void const **chosen_dtb,
-    size_t *chosen_dtb_size);
+    dtb_info_t *dtb_info);
 
 /* Platform functions */
 void platform_init(void);

elfloader-tool/src/arch-arm/smp_boot.c

@@ -22,8 +22,7 @@ static volatile int non_boot_lock = 0;
 
 void arm_disable_dcaches(void);
 
-extern void const *dtb;
-extern uint32_t dtb_size;
+extern dtb_info_t dtb_info;
 
 WEAK void non_boot_init(void) {}
 
@@ -59,7 +58,8 @@ void non_boot_main(void)
     /* Jump to the kernel. */
     ((init_arm_kernel_t)kernel_info.virt_entry)(user_info.phys_region_start,
                                                 user_info.phys_region_end, user_info.phys_virt_offset,
-                                                user_info.virt_entry, (paddr_t)dtb, dtb_size);
+                                                user_info.virt_entry,
+                                                (word_t)dtb_info.phys_base, dtb_info.size);
 
     printf("AP Kernel returned back to the elf-loader.\n");
     abort();

elfloader-tool/src/arch-arm/sys_boot.c

@@ -32,8 +32,7 @@ char core_stack_alloc[CONFIG_MAX_NUM_NODES][BIT(PAGE_BITS)];
 
 struct image_info kernel_info;
 struct image_info user_info;
-void const *dtb;
-size_t dtb_size;
+dtb_info_t dtb_info;
 
 extern void finish_relocation(int offset, void *_dynamic, unsigned int total_offset);
 void continue_boot(int was_relocated);
@@ -101,8 +100,6 @@ void relocate_below_kernel(void)
  */
 void main(UNUSED void *arg)
 {
-    void *bootloader_dtb = NULL;
-
     /* initialize platform to a state where we can print to a UART */
     initialise_devices();
     platform_init();
@@ -112,13 +109,22 @@ void main(UNUSED void *arg)
     print_cpuid();
     printf("  paddr=[%p..%p]\n", _text, _end - 1);
 
+    /* Assume by default, that no DTB is provided from a previous
+     * bootloader stage. Since 0 is a valid physical address, the size
+     * field is used to indicate if the address is valid. The value -1
+     * is to be used if the actual size is not known.
+     */
+    dtb_info.phys_base = 0;
+    dtb_info.size = 0;
+
 #if defined(CONFIG_IMAGE_UIMAGE)
 
     /* U-Boot passes a DTB. Ancient bootloaders may pass atags. When booting via
      * bootelf argc is NULL.
      */
     if (arg && (DTB_MAGIC == *(uint32_t *)arg)) {
-        bootloader_dtb = arg;
+        dtb_info.phys_base = (paddr_t)arg;
+        dtb_info.size = (size_t)(-1);
     }
 
 #elif defined(CONFIG_IMAGE_EFI)
@@ -128,20 +134,24 @@ void main(UNUSED void *arg)
         abort();
     }
 
-    bootloader_dtb = efi_get_fdt();
+    /* For EFI, the DTB address is not supposed to be 0. */
+    void *efi_dtb = efi_get_fdt();
+    if (efi_dtb) {
+        dtb_info.phys_base = (paddr_t)efi_dtb;
+        dtb_info.size = (size_t)(-1);
+    }
 
 #endif
 
-    if (bootloader_dtb) {
-        printf("  dtb=%p\n", bootloader_dtb);
+    if (0 != dtb_info.size) {
+        printf("  dtb=%p\n", dtb_info.phys_base);
     } else {
         printf("No DTB passed in from boot loader.\n");
     }
 
     /* Unpack ELF images into memory. */
     unsigned int num_apps = 0;
-    int ret = load_images(&kernel_info, &user_info, 1, &num_apps,
-                          bootloader_dtb, &dtb, &dtb_size);
+    int ret = load_images(&kernel_info, &user_info, 1, &num_apps, &dtb_info);
     if (0 != ret) {
         printf("ERROR: image loading failed\n");
         abort();
@@ -218,8 +228,8 @@ void continue_boot(int was_relocated)
                                                 user_info.phys_region_end,
                                                 user_info.phys_virt_offset,
                                                 user_info.virt_entry,
-                                                (word_t)dtb,
-                                                dtb_size);
+                                                (word_t)dtb_info.phys_base,
+                                                dtb_info.size);
 
     /* We should never get here. */
     printf("ERROR: Kernel returned back to the ELF Loader\n");

elfloader-tool/src/arch-riscv/boot.c

@@ -60,8 +60,7 @@ unsigned long l2pt_elf[PTES_PER_PT] __attribute__((aligned(4096)));
 char elfloader_stack_alloc[BIT(CONFIG_KERNEL_STACK_BITS)];
 
 /* first HART will initialise these */
-void const *dtb = NULL;
-size_t dtb_size = 0;
+dtb_info_t dtb_info;
 
 /*
  * overwrite the default implementation for abort()
@@ -194,10 +193,12 @@ static int run_elfloader(UNUSED int hart_id, void *bootloader_dtb)
 {
     int ret;
 
+    dtb_info.phys_base = (paddr_t)bootloader_dtb;
+    dtb_info.size = (size_t)(-1);
+
     /* Unpack ELF images into memory. */
     unsigned int num_apps = 0;
-    ret = load_images(&kernel_info, &user_info, 1, &num_apps,
-                      bootloader_dtb, &dtb, &dtb_size);
+    ret = load_images(&kernel_info, &user_info, 1, &num_apps, &dtb_info);
     if (0 != ret) {
         printf("ERROR: image loading failed, code %d\n", ret);
         return -1;
@@ -243,8 +244,8 @@ static int run_elfloader(UNUSED int hart_id, void *bootloader_dtb)
                                                   user_info.phys_region_end,
                                                   user_info.phys_virt_offset,
                                                   user_info.virt_entry,
-                                                  (word_t)dtb,
-                                                  dtb_size
+                                                  (word_t)dtb_info.phys_base,
+                                                  dtb_info.size
 #if CONFIG_MAX_NUM_NODES > 1
                                                   ,
                                                   hart_id,
@@ -278,8 +279,8 @@ void secondary_entry(int hart_id, int core_id)
                                                   user_info.phys_region_end,
                                                   user_info.phys_virt_offset,
                                                   user_info.virt_entry,
-                                                  (word_t)dtb,
-                                                  dtb_size,
+                                                  (word_t)dtb_info.phys_base,
+                                                  dtb_info.size,
                                                   hart_id,
                                                   core_id
                                                  );

elfloader-tool/src/common.c

@@ -384,9 +384,7 @@ int load_images(
     struct image_info *user_info,
     unsigned int max_user_images,
     unsigned int *num_images,
-    void const *bootloader_dtb,
-    void const **chosen_dtb,
-    size_t *chosen_dtb_size)
+    dtb_info_t *dtb_info)
 {
     int ret;
     uint64_t kernel_phys_start, kernel_phys_end;
@@ -434,31 +432,32 @@ int load_images(
 
 #ifdef CONFIG_ELFLOADER_INCLUDE_DTB
 
-    if (chosen_dtb) {
-        printf("Looking for DTB in CPIO archive...");
-        /*
-         * Note the lack of newline in the above printf().  Normally one would
-         * have an fflush(stdout) here to ensure that the message shows up on a
-         * line-buffered stream (which is the POSIX default on terminal
-         * devices).  But we are freestanding (on the "bare metal"), and using
-         * our own unbuffered printf() implementation.
-         */
-        dtb = cpio_get_file(cpio, cpio_len, "kernel.dtb", NULL);
-        if (dtb == NULL) {
-            printf("not found.\n");
-        } else {
-            has_dtb_cpio = 1;
-            printf("found at %p.\n", dtb);
-        }
+    printf("Looking for DTB in CPIO archive...");
+    /*
+     * Note the lack of newline in the above printf().  Normally one would
+     * have an fflush(stdout) here to ensure that the message shows up on a
+     * line-buffered stream (which is the POSIX default on terminal
+     * devices).  But we are freestanding (on the "bare metal"), and using
+     * our own unbuffered printf() implementation.
+     */
+    dtb = cpio_get_file(cpio, cpio_len, "kernel.dtb", NULL);
+    if (dtb == NULL) {
+        printf("not found.\n");
+    } else {
+        has_dtb_cpio = 1;
+        printf("found at %p.\n", dtb);
     }
 
 #endif /* CONFIG_ELFLOADER_INCLUDE_DTB */
 
-    if (chosen_dtb && !dtb && bootloader_dtb) {
-        /* Use the bootloader's DTB if we are not using the DTB in the CPIO
-         * archive.
-         */
-        dtb = bootloader_dtb;
+    /* If we don't have a DTB here, use the one a bootloader might have
+     * provided. Since 0 is a valid physical address, the size field is used to
+     * determin if the address is valid. A size of -1 indicates, that the actual
+     * size is not known - which is usually the case, because a bootloader often
+     * just passes an address.
+     */
+    if (!dtb && (dtb_info->size > 0)) {
+        dtb = (void const *)dtb_info->phys_base;
     }
 
     /*
@@ -489,9 +488,11 @@ int load_images(
 
         printf("Loaded DTB from %p.\n", dtb);
         printf("   paddr=[%p..%p]\n", dtb_phys_start, dtb_phys_end - 1);
-        *chosen_dtb = (void *)dtb_phys_start;
-        *chosen_dtb_size = dtb_size;
+        dtb_info->phys_base = dtb_phys_start;
+        dtb_info->size = dtb_size;
     } else {
+        dtb_info->phys_base = 0;
+        dtb_info->size = 0;
         next_phys_addr = ROUND_UP(kernel_phys_end, PAGE_BITS);
     }