src/arch/riscv/fit_payload.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2
   3 #include <commonlib/bsd/compression.h>
   4 #include <console/console.h>
   5 #include <bootmem.h>
   6 #include <program_loading.h>
   7 #include <fit.h>
   8 #include <endian.h>
   9
  10 /* Implements a Berkeley Boot Loader (BBL) compatible payload loading */
  11
  12 #define MAX_KERNEL_SIZE (64*MiB)
  13
  14 #if CONFIG(ARCH_RISCV_RV32)
  15 #define SECTION_ALIGN (4 * MiB)
  16 #endif
  17 #if CONFIG(ARCH_RISCV_RV64)
  18 #define SECTION_ALIGN (2 * MiB)
  19 #endif
  20
  21 static size_t get_kernel_size(const struct fit_image_node *node)
  22 {
  23         /*
  24          * Since we don't have a way to determine the uncompressed size of the
  25          * kernel, we have to keep as much memory as possible free for use by
  26          * the kernel immediately after the end of the kernel image. The amount
  27          * of space required will vary depending on selected features, and is
  28          * effectively unbound.
  29          */
  30
  31         printk(BIOS_INFO,
  32                "FIT: Leaving additional %u MiB of free space after kernel.\n",
  33                MAX_KERNEL_SIZE >> 20);
  34
  35         return node->size + MAX_KERNEL_SIZE;
  36 }
  37
  38 /**
  39  * Place the region in free memory range.
  40  *
  41  * The caller has to set region->offset to the minimum allowed address.
  42  */
  43 static bool fit_place_mem(const struct range_entry *r, void *arg)
  44 {
  45         struct region *region = arg;
  46         resource_t start;
  47
  48         if (range_entry_tag(r) != BM_MEM_RAM)
  49                 return true;
  50
  51         /* Section must be aligned at page boundary */
  52         start = ALIGN_UP(MAX(region->offset, range_entry_base(r)), SECTION_ALIGN);
  53
  54         if (start + region->size < range_entry_end(r)) {
  55                 region->offset = (size_t)start;
  56                 return false;
  57         }
  58
  59         return true;
  60 }
  61
  62 bool fit_payload_arch(struct prog *payload, struct fit_config_node *config,
  63                       struct region *kernel,
  64                       struct region *fdt,
  65                       struct region *initrd)
  66 {
  67         void *arg = NULL;
  68
  69         if (!config->fdt || !fdt) {
  70                 printk(BIOS_CRIT, "Providing a valid FDT is mandatory to "
  71                        "boot a RISC-V kernel!\n");
  72                 return false;
  73                 /* TODO: Fall back to the ROM FDT? */
  74         }
  75
  76         /* Update kernel size from image header, if possible */
  77         kernel->size = get_kernel_size(config->kernel);
  78         printk(BIOS_DEBUG, "FIT: Using kernel size of 0x%zx bytes\n",
  79                kernel->size);
  80
  81         /*
  82          * The code assumes that bootmem_walk provides a sorted list of memory
  83          * regions, starting from the lowest address.
  84          * The order of the calls here doesn't matter, as the placement is
  85          * enforced in the called functions.
  86          * For details check code on top.
  87          */
  88         kernel->offset = 0;
  89         if (!bootmem_walk(fit_place_mem, kernel))
  90                 return false;
  91
  92         /* Mark as reserved for future allocations. */
  93         bootmem_add_range(kernel->offset, kernel->size, BM_MEM_PAYLOAD);
  94
  95         /* Place FDT and INITRD after kernel. */
  96
  97         /* Place INITRD */
  98         if (config->ramdisk) {
  99                 initrd->offset = kernel->offset + kernel->size;
 100
 101                 if (!bootmem_walk(fit_place_mem, initrd))
 102                         return false;
 103                 /* Mark as reserved for future allocations. */
 104                 bootmem_add_range(initrd->offset, initrd->size, BM_MEM_PAYLOAD);
 105         }
 106
 107         /* Place FDT */
 108         fdt->offset = kernel->offset + kernel->size;
 109
 110         if (!bootmem_walk(fit_place_mem, fdt))
 111                 return false;
 112         /* Mark as reserved for future allocations. */
 113         bootmem_add_range(fdt->offset, fdt->size, BM_MEM_PAYLOAD);
 114
 115         /* Kernel expects FDT as argument */
 116         arg = (void *)fdt->offset;
 117
 118         prog_set_entry(payload, (void *)kernel->offset, arg);
 119
 120         bootmem_dump_ranges();
 121
 122         return true;
 123 }