ATF load_serialno internal API

baou · September 15, 2017, 12:07pm

Hi,

In the past on Hikey there was this load_serialno internal API which could be used to retrieve board serial number

96boards/arm-trusted-firmware/blob/hikey/plat/hikey/plat_io_storage.c#L587

    
      
          {
          	int result;
          
          
	memset((void *)SPARSE_FILL_BUFFER_ADDRESS, 0, 512);
          	memcpy((void *)SPARSE_FILL_BUFFER_ADDRESS, (void *)addr, length);
          	result = flush_single_image(NORMAL_EMMC_NAME, SPARSE_FILL_BUFFER_ADDRESS,
          				    SERIALNO_OFFSET, 512);
          	return result;
          }
          
          
char *load_serialno(void)
          {
          	uintptr_t img_handle, spec = 0;
          	size_t bytes_read;
          	struct random_serial_num *random = NULL;
          	int result;
          
          
	result = plat_get_image_source(NORMAL_EMMC_NAME, &emmc_dev_handle,
          				       &spec);
          	if (result) {
          		NOTICE("failed to open emmc user data area\n");

Usually this was set through some OEM fastboot command.

Now moving to Hikey960 it seems this API does not exist in ARM ATF.
There exists a board id read but no such serial number read function.

github.com

ARM-software/arm-trusted-firmware/blob/master/plat/hisilicon/hikey960/hikey960_private.h#L29

    
      
          			unsigned long coh_start,
          			unsigned long coh_limit);
          void hikey960_init_mmu_el3(unsigned long total_base,
          			unsigned long total_size,
          			unsigned long ro_start,
          			unsigned long ro_limit,
          			unsigned long coh_start,
          			unsigned long coh_limit);
          void hikey960_io_setup(void);
          int hikey960_read_boardid(unsigned int *id);
          int hikey960_set_fip_addr(unsigned int image_id, const char *name);
          void hikey960_clk_init(void);
          void hikey960_pmu_init(void);
          void hikey960_regulator_enable(void);
          void hikey960_tzc_init(void);
          void hikey960_peri_init(void);
          void hikey960_pinmux_init(void);
          void hikey960_gpio_init(void);
          void set_retention_ticks(unsigned int val);
          void clr_retention_ticks(unsigned int val);
          void clr_ex(void);

On Hikey there is a prototype but no implementation for the same.

github.com

ARM-software/arm-trusted-firmware/blob/master/plat/hisilicon/hikey/hikey_private.h#L49

    
      
          			unsigned long total_size,
          			unsigned long ro_start,
          			unsigned long ro_limit,
          			unsigned long coh_start,
          			unsigned long coh_limit);
          
          
void hikey_ddr_init(unsigned int ddr_freq);
          void hikey_io_setup(void);
          
          
void hikey_sp804_init(void);
          void hikey_gpio_init(void);
          void hikey_pmussi_init(void);
          void hikey_hi6553_init(void);
          void init_mmc0_pll(void);
          void reset_mmc0_clk(void);
          void init_media_clk(void);
          void init_mmc1_pll(void);
          void reset_mmc1_clk(void);
          void hikey_mmc_pll_init(void);
          void hikey_rtc_init(void);

I assume with flash storage moving to UFS, there may be changes related to partitions layout and possibly location for the serial number.

Is adding the serial number a matter of 96boards BSP work ?
Would this happen in 96boards github fork project?

Thanks & Regards.

danielt · September 15, 2017, 3:14pm

load_serialno() is only ever called on a hikey by a special piece of code in BL1 that is reachable only when we don’t boot from eMMC (i.e. during the debrick proceedure).

To be honest there’s a strong argument that code like this doesn’t belong in ARM trusted firmware in the first place (fastboot could probably be implemented by the BL31 payload even when booting from USB). As such you should not assume that there is any plan to implement something similar for hikey960; even if it were implemented as a temporary convenience in the long term this type of code should be removed (otherwise we become misaligned with upstream ARM TF).