src/mainboard/opencellular/elgon/bootblock.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <bootblock_common.h>
   4 #include <soc/soc.h>
   5 #include <soc/spi.h>
   6 #include <soc/uart.h>
   7 #include <soc/gpio.h>
   8 #include <spi_flash.h>
   9 #include <console/console.h>
  10 #include <fmap.h>
  11 #include "mainboard.h"
  12
  13 void bootblock_mainboard_early_init(void)
  14 {
  15         /* Route UART0 to CON1 */
  16         gpio_output(ELGON_GPIO_UART_SEL, 0);
  17
  18         /* Turn off error LED */
  19         gpio_output(ELGON_GPIO_ERROR_LED, 0);
  20
  21         if (CONFIG(BOOTBLOCK_CONSOLE)) {
  22                 if (!uart_is_enabled(CONFIG_UART_FOR_CONSOLE))
  23                         uart_setup(CONFIG_UART_FOR_CONSOLE, CONFIG_TTYS0_BAUD);
  24         }
  25 }
  26
  27 static void configure_spi_flash(void)
  28 {
  29         /* The maximum SPI frequency for error-free transmission is at 30 MHz */
  30         spi_init_custom(0, // bus
  31                         28000000, // speed Hz
  32                         0, // idle low disabled
  33                         0, // zero idle cycles between transfers
  34                         0, // MSB first
  35                         0, // Chip select 0
  36                         1); // assert is high
  37
  38         /* Route SPI to SoC */
  39         gpio_output(ELGON_GPIO_SPI_MUX, 1);
  40 }
  41
  42 /**
  43  * Handle flash write protection.
  44  * This code verifies the write-protection on each boot.
  45  * Enabling the write protection does only run on the first boot.
  46  * An error is fatal as it breaks the Chain Of Trust.
  47  */
  48 static void protect_ro_rgn_spi_flash(void)
  49 {
  50         const struct spi_flash *flash = boot_device_spi_flash();
  51         const char *fmapname = "WP_RO";
  52         struct region ro_rgn;
  53
  54         if (fmap_locate_area(fmapname, &ro_rgn)) {
  55                 printk(BIOS_ERR, "%s: No %s FMAP section.\n", __func__,
  56                         fmapname);
  57                 die("Can't verify flash protections!");
  58         }
  59
  60         u8 reg8 = 0;
  61         spi_flash_status(flash, &reg8);
  62
  63         /* Check if SRP0 is set and RO region is protected */
  64         if (!(reg8 & 0x80) ||
  65             spi_flash_is_write_protected(flash, &ro_rgn) != 1) {
  66                 printk(BIOS_WARNING, "%s: FMAP section %s is not write-protected\n",
  67                          __func__, fmapname);
  68
  69                 /*
  70                 * Need to protect flash region :
  71                 * WP_RO read only and use /WP pin
  72                 * non-volatile programming
  73                 */
  74                 if (spi_flash_set_write_protected(flash, &ro_rgn,
  75                     SPI_WRITE_PROTECTION_PIN) != 0)
  76                         die("Failed to write-protect WP_RO region!");
  77         }
  78         printk(BIOS_INFO, "%s: FMAP section %s is write-protected\n",
  79                __func__, fmapname);
  80 }
  81
  82 void bootblock_mainboard_init(void)
  83 {
  84         configure_spi_flash();
  85         protect_ro_rgn_spi_flash();
  86 }