Re: [PATCH 1/4] board: starfive: function to read eMMC size

On Mon, Apr 15, 2024 at 4:50 AM Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:

The EEPROM provides information about the size of the EEPROM.

"The EEPROM provides information about the size of the eMMC."

Provide a new function get_mmc_size_from_eeprom() to read it.

Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com

arch/riscv/include/asm/arch-jh7110/eeprom.h | 7 +++++++ board/starfive/visionfive2/Kconfig | 9 +++++++++ .../visionfive2/visionfive2-i2c-eeprom.c | 18 ++++++++++++++++++ 3 files changed, 34 insertions(+)

diff --git a/arch/riscv/include/asm/arch-jh7110/eeprom.h b/arch/riscv/include/asm/arch-jh7110/eeprom.h index 62d184aeb57..17395d4269e 100644 --- a/arch/riscv/include/asm/arch-jh7110/eeprom.h +++ b/arch/riscv/include/asm/arch-jh7110/eeprom.h @@ -12,6 +12,13 @@ u8 get_pcb_revision_from_eeprom(void); u32 get_ddr_size_from_eeprom(void);

+/**

• • get_mmc_size_from_eeprom() - read MMC size form EEPROM
• • @return: size in GiB or 0 on error.
• */

+u32 get_mmc_size_from_eeprom(void);

/**

• get_product_id_from_eeprom - get product ID string

diff --git a/board/starfive/visionfive2/Kconfig b/board/starfive/visionfive2/Kconfig index 2186a939646..d7e8a7a7d78 100644 --- a/board/starfive/visionfive2/Kconfig +++ b/board/starfive/visionfive2/Kconfig @@ -50,4 +50,13 @@ config BOARD_SPECIFIC_OPTIONS # dummy imply PHY_LIB imply PHY_MSCC

+config STARFIVE_NO_EMMC

•   bool "Report eMMC size as zero"
  

•   help
  

•     The serial number string in the EEPROM is meant to report the
  

•     size of onboard eMMC. Unfortunately some Milk-V Mars CM Lite
  

•     modules without eMMC show a non-zero size here.
  

•     Set to 'Y' if you have a Mars CM Lite module.
  

endif diff --git a/board/starfive/visionfive2/visionfive2-i2c-eeprom.c b/board/starfive/visionfive2/visionfive2-i2c-eeprom.c index ddef7d61235..cd3d8bd51a6 100644 --- a/board/starfive/visionfive2/visionfive2-i2c-eeprom.c +++ b/board/starfive/visionfive2/visionfive2-i2c-eeprom.c @@ -548,6 +548,24 @@ u32 get_ddr_size_from_eeprom(void) return hextoul(&pbuf.eeprom.atom1.data.pstr[14], NULL); }

+u32 get_mmc_size_from_eeprom(void) +{

•   u32 size;
  

•   if (IS_ENABLED(CONFIG_STARFIVE_NO_EMMC))
  

•           return 0;
  

•   if (read_eeprom())
  

•           return 0;
  

•   size = dectoul(&pbuf.eeprom.atom1.data.pstr[19], NULL);
  

•   if (pbuf.eeprom.atom1.data.pstr[21] == 'T')
  

•           size <<= 10;
  

•   return size;
  

+}

U_BOOT_LONGHELP(mac, "\n" " - display EEPROM content\n" -- 2.43.0

Fixed-position parsing on a data format of ordered variable length hyphen-delimited fields. Notable is that some Pine64 Star64 and Milk-V Mars CM Lite boards shipped with uninitialized or wrong EEPROM data; further the EEPROM Write Protect can be trivially disabled and arbitrary data written i.e. with a paperclip then `mac` command. Could this code be generalized to split fields on hyphen character better expressing the expected data format or is that unwanted complexity and code size?