src/drivers/intel/gma/vbt.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <device/pci_ops.h>
   4 #include <device/device.h>
   5 #include <string.h>
   6 #include <device/pci.h>
   7 #include <drivers/intel/gma/opregion.h>
   8
   9 #include "i915.h"
  10 #include "intel_bios.h"
  11
  12 static size_t generate_vbt(const struct i915_gpu_controller_info *const conf,
  13                            struct vbt_header *const head,
  14                            const char *const idstr)
  15 {
  16         u8 *ptr;
  17
  18         memset(head, 0, sizeof(*head));
  19
  20         memset(head->signature, ' ', sizeof(head->signature));
  21         memcpy(head->signature, idstr,
  22                 MIN(strlen(idstr), sizeof(head->signature)));
  23         head->version = 100;
  24         head->header_size = sizeof(*head);
  25         head->bdb_offset = sizeof(*head);
  26
  27         struct bdb_header *const bdb_head = (struct bdb_header *)(head + 1);
  28         memset(bdb_head, 0, sizeof(*bdb_head));
  29         memcpy(bdb_head->signature, "BIOS_DATA_BLOCK ", 16);
  30         bdb_head->version = 0xa8;
  31         bdb_head->header_size = sizeof(*bdb_head);
  32
  33         ptr = (u8 *)(bdb_head + 1);
  34
  35         ptr[0] = BDB_GENERAL_FEATURES;
  36         ptr[1] = sizeof(struct bdb_general_features);
  37         ptr[2] = sizeof(struct bdb_general_features) >> 8;
  38         ptr += 3;
  39
  40         struct bdb_general_features *const genfeat =
  41                 (struct bdb_general_features *)ptr;
  42         memset(genfeat, 0, sizeof(*genfeat));
  43         genfeat->panel_fitting = 3;
  44         genfeat->flexaim = 1;
  45         genfeat->download_ext_vbt = 1;
  46         genfeat->enable_ssc = conf->use_spread_spectrum_clock;
  47         genfeat->ssc_freq = CONFIG(INTEL_GMA_SSC_ALTERNATE_REF);
  48         genfeat->rsvd10 = 0x4;
  49         genfeat->legacy_monitor_detect = 1;
  50         genfeat->int_crt_support = 1;
  51         genfeat->dp_ssc_enb = 1;
  52
  53         ptr += sizeof(*genfeat);
  54
  55         bdb_head->bdb_size = ptr - (u8 *)bdb_head;
  56         head->vbt_size = ptr - (u8 *)head;
  57         head->vbt_checksum = 0;
  58         return ptr - (u8 *)head;
  59 }
  60
  61 void
  62 generate_fake_intel_oprom(const struct i915_gpu_controller_info *const conf,
  63                           struct device *const dev, const char *const idstr)
  64 {
  65         optionrom_header_t *const oh = (void *)PCI_VGA_RAM_IMAGE_START;
  66
  67         memset(oh, 0, 8192);
  68
  69         oh->signature = PCI_ROM_HDR;
  70         oh->pcir_offset = 0x40;
  71         oh->vbt_offset = 0x80;
  72
  73         optionrom_pcir_t *const pcir = (void *)((u8 *)oh + oh->pcir_offset);
  74         pcir->signature = 0x52494350;   // PCIR
  75         pcir->vendor = dev->vendor;
  76         pcir->device = dev->device;
  77         pcir->length = sizeof(*pcir);
  78         pcir->revision = pci_read_config8(dev, PCI_CLASS_REVISION);
  79         pcir->classcode[0] = dev->class;
  80         pcir->classcode[1] = dev->class >> 8;
  81         pcir->classcode[2] = dev->class >> 16;
  82         pcir->indicator = 0x80;
  83
  84         const size_t vbt_size =
  85                 generate_vbt(conf, (void *)((u8 *)oh + oh->vbt_offset), idstr);
  86         const size_t fake_oprom_size =
  87                 DIV_ROUND_UP(oh->vbt_offset + vbt_size, 512);
  88         oh->size = fake_oprom_size;
  89         pcir->imagelength = fake_oprom_size;
  90 }