src/arch/arm/fit_payload.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #include <bootmem.h>
   4 #include <program_loading.h>
   5 #include <fit.h>
   6 #include <symbols.h>
   7
   8 /**
   9  * Place the region in free memory range.
  10  */
  11 static bool fit_place_mem(const struct range_entry *r, void *arg)
  12 {
  13         struct region *region = arg;
  14         resource_t start;
  15
  16         if (range_entry_tag(r) != BM_MEM_RAM)
  17                 return true;
  18
  19         /* Linux 4.15 doesn't like 4KiB alignment. Align to 1 MiB for now. */
  20         start = ALIGN_UP(MAX(region->offset, range_entry_base(r)), 1 * MiB);
  21
  22         if (start + region->size < range_entry_end(r)) {
  23                 region->offset = (size_t)start;
  24                 return false;
  25         }
  26
  27         return true;
  28 }
  29
  30 bool fit_payload_arch(struct prog *payload, struct fit_config_node *config,
  31                       struct region *kernel,
  32                       struct region *fdt,
  33                       struct region *initrd)
  34 {
  35         void *arg = NULL;
  36
  37         /**
  38          * The kernel ARM documentation recommends loading the kernel above 32MiB
  39          * in order to avoid the need to need to relocate prior to decompression.
  40          */
  41         kernel->offset = (uintptr_t)_dram + 32 * MiB;
  42
  43         /**
  44          * The code assumes that bootmem_walk provides a sorted list of memory
  45          * regions, starting from the lowest address.
  46          * The order of the calls here doesn't matter, as the placement is
  47          * enforced in the called functions.
  48          * For details check code on top.
  49          */
  50         if (!bootmem_walk(fit_place_mem, kernel))
  51                 return false;
  52
  53         /* Mark as reserved for future allocations. */
  54         bootmem_add_range(kernel->offset, kernel->size, BM_MEM_PAYLOAD);
  55
  56         /**
  57          * To ensure the fdt is not overwritten by the kernel decompressor, place
  58          * the fdt above the 128 MB from the start of RAM, as recommended by the
  59          * kernel documentation.
  60          */
  61         fdt->offset = (uintptr_t)_dram + 128 * MiB;
  62
  63         if (!bootmem_walk(fit_place_mem, fdt))
  64                 return false;
  65
  66         /* Mark as reserved for future allocations. */
  67         bootmem_add_range(fdt->offset, fdt->size, BM_MEM_PAYLOAD);
  68
  69         /* Place INITRD */
  70         if (config->ramdisk) {
  71                 initrd->offset = fdt->offset + fdt->size;
  72
  73                 if (!bootmem_walk(fit_place_mem, initrd))
  74                         return false;
  75
  76                 /* Mark as reserved for future allocations. */
  77                 bootmem_add_range(initrd->offset, initrd->size, BM_MEM_PAYLOAD);
  78         }
  79
  80         /* Kernel expects FDT as argument */
  81         arg = (void *)fdt->offset;
  82
  83         prog_set_entry(payload, (void *)kernel->offset, arg);
  84
  85         bootmem_dump_ranges();
  86
  87         return true;
  88 }