diff options
| -rw-r--r-- | arch/arm/mach-sunxi/board.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c index 755d7d78ff1..173e946465d 100644 --- a/arch/arm/mach-sunxi/board.c +++ b/arch/arm/mach-sunxi/board.c @@ -346,6 +346,89 @@ __weak void sunxi_sram_init(void) { } +/* + * When booting from an eMMC boot partition, the SPL puts the same boot + * source code into SRAM A1 as when loading the SPL from the normal + * eMMC user data partition: 0x2. So to know where we have been loaded + * from, we repeat the BROM algorithm here: checking for a valid eGON boot + * image at offset 0 of a (potentially) selected boot partition. + * If any of the conditions is not met, it must have been the eMMC user + * data partition. + */ +static bool sunxi_valid_emmc_boot(struct mmc *mmc) +{ + struct blk_desc *bd = mmc_get_blk_desc(mmc); + uint32_t *buffer = (void *)(uintptr_t)CONFIG_SYS_TEXT_BASE; + struct boot_file_head *egon_head = (void *)buffer; + int bootpart = EXT_CSD_EXTRACT_BOOT_PART(mmc->part_config); + uint32_t spl_size, emmc_checksum, chksum = 0; + ulong count; + + /* The BROM requires BOOT_ACK to be enabled. */ + if (!EXT_CSD_EXTRACT_BOOT_ACK(mmc->part_config)) + return false; + + /* + * The BOOT_BUS_CONDITION register must be 4-bit SDR, with (0x09) + * or without (0x01) high speed timings. + */ + if ((mmc->ext_csd[EXT_CSD_BOOT_BUS_WIDTH] & 0x1b) != 0x01 && + (mmc->ext_csd[EXT_CSD_BOOT_BUS_WIDTH] & 0x1b) != 0x09) + return false; + + /* Partition 0 is the user data partition, bootpart must be 1 or 2. */ + if (bootpart != 1 && bootpart != 2) + return false; + + /* Failure to switch to the boot partition is fatal. */ + if (mmc_switch_part(mmc, bootpart)) + return false; + + /* Read the first block to do some sanity checks on the eGON header. */ + count = blk_dread(bd, 0, 1, buffer); + if (count != 1 || !sunxi_egon_valid(egon_head)) + return false; + + /* Read the rest of the SPL now we know it's halfway sane. */ + spl_size = buffer[4]; + count = blk_dread(bd, 1, DIV_ROUND_UP(spl_size, bd->blksz) - 1, + buffer + bd->blksz / 4); + + /* Save the checksum and replace it with the "stamp value". */ + emmc_checksum = buffer[3]; + buffer[3] = 0x5f0a6c39; + + /* The checksum is a simple ignore-carry addition of all words. */ + for (count = 0; count < spl_size / 4; count++) + chksum += buffer[count]; + + debug("eMMC boot part SPL checksum: stored: 0x%08x, computed: 0x%08x\n", + emmc_checksum, chksum); + + return emmc_checksum == chksum; +} + +u32 spl_mmc_boot_mode(struct mmc *mmc, const u32 boot_device) +{ + static u32 result = ~0; + + if (result != ~0) + return result; + + result = MMCSD_MODE_RAW; + if (!IS_SD(mmc) && IS_ENABLED(CONFIG_SUPPORT_EMMC_BOOT)) { + if (sunxi_valid_emmc_boot(mmc)) + result = MMCSD_MODE_EMMCBOOT; + else + mmc_switch_part(mmc, 0); + } + + debug("%s(): %s part\n", __func__, + result == MMCSD_MODE_RAW ? "user" : "boot"); + + return result; +} + void board_init_f(ulong dummy) { sunxi_sram_init(); |