[PATCHv2] zynqmp: restore the jtag interface

[Jorge Ramirez-Ortiz, Foundries]

On 13/10/21, Michal Simek wrote:
> 
> 
> On 10/13/21 10:25, Jorge Ramirez-Ortiz wrote:
> > When boot.bin is configured for secure boot the CSU will disable the
> > JTAG interface on all cases.
> > 
> > Some boards might rely on this interface for flashing to QSPI in which
> > case those systems might end up bricked during development.
> > 
> > This commit will restore the interface under CSU control
> > 
> > Signed-off-by: Jorge Ramirez-Ortiz <jorge at foundries.io>
> > ---
> 
> I can't see changelog here. What has changed in 3 minutes between v1 and v2?

Not in 3 minutes but in 3 months: the first version was submited on
2021-07-16.

The first patch sent this morning was missing the "v2" tag hence why I
resent three minutes later.

v2 addresses the issues you mentioned with the original patch from
July.

	v2
	--
	    Macros added to hardware.h
	    Used CONFIG_IS_ENABLED where possible
	    Fixed Kconfig identation
	    Removed unnecessary Kconfig default

> 
> >   arch/arm/mach-zynqmp/Kconfig                 |  8 +++++
> >   arch/arm/mach-zynqmp/include/mach/hardware.h | 31 +++++++++++++++-----
> >   board/xilinx/zynqmp/zynqmp.c                 | 20 ++++++++++++-
> >   3 files changed, 51 insertions(+), 8 deletions(-)
> > 
> > diff --git a/arch/arm/mach-zynqmp/Kconfig b/arch/arm/mach-zynqmp/Kconfig
> > index f7b08db355..ee0895d9a2 100644
> > --- a/arch/arm/mach-zynqmp/Kconfig
> > +++ b/arch/arm/mach-zynqmp/Kconfig
> > @@ -149,6 +149,14 @@ config SPL_ZYNQMP_ALT_BOOTMODE_ENABLED
> >   	  Overwrite bootmode selected via boot mode pins to tell SPL what should
> >   	  be the next boot device.
> > +config SPL_ZYNQMP_RESTORE_JTAG
> > +	bool "Restore JTAG"
> > +	depends on SPL
> > +	help
> > +	 Booting SPL in secure mode causes the CSU to disable the JTAG interface
> > +	 even if no eFuses were burnt. This option restores the interface if
> > +	 possible.
> > +
> >   config ZYNQ_SDHCI_MAX_FREQ
> >   	default 200000000
> > diff --git a/arch/arm/mach-zynqmp/include/mach/hardware.h b/arch/arm/mach-zynqmp/include/mach/hardware.h
> > index eebf38551c..e6a3ee4a57 100644
> > --- a/arch/arm/mach-zynqmp/include/mach/hardware.h
> > +++ b/arch/arm/mach-zynqmp/include/mach/hardware.h
> > @@ -39,20 +39,26 @@
> >   #define RESET_REASON_INTERNAL	BIT(1)
> >   #define RESET_REASON_EXTERNAL	BIT(0)
> > +#define CRLAPB_DBG_LPD_CTRL_SETUP_CLK	0x01002002
> > +#define CRLAPB_RST_LPD_DBG_RESET	0
> > +
> >   struct crlapb_regs {
> >   	u32 reserved0[36];
> >   	u32 cpu_r5_ctrl; /* 0x90 */
> > -	u32 reserved1[37];
> > +	u32 reserved1[7];
> > +	u32 dbg_lpd_ctrl; /* 0xB0 */
> > +	u32 reserved2[29];
> >   	u32 timestamp_ref_ctrl; /* 0x128 */
> > -	u32 reserved2[53];
> > +	u32 reserved3[53];
> >   	u32 boot_mode; /* 0x200 */
> > -	u32 reserved3_0[7];
> > +	u32 reserved4_0[7];
> >   	u32 reset_reason; /* 0x220 */
> > -	u32 reserved3_1[6];
> > +	u32 reserved4_1[6];
> >   	u32 rst_lpd_top; /* 0x23C */
> > -	u32 reserved4[4];
> > +	u32 rst_lpd_dbg; /* 0x240 */
> > +	u32 reserved5[3];
> >   	u32 boot_pin_ctrl; /* 0x250 */
> > -	u32 reserved5[21];
> > +	u32 reserved6[21];
> >   };
> >   #define crlapb_base ((struct crlapb_regs *)ZYNQMP_CRL_APB_BASEADDR)
> > @@ -141,12 +147,23 @@ struct apu_regs {
> >   #define ZYNQMP_SILICON_VER_MASK		0xF
> >   #define ZYNQMP_SILICON_VER_SHIFT	0
> > +#define CSU_JTAG_SEC_GATE_DISABLE	GENMASK(7, 0)
> > +#define CSU_JTAG_DAP_ENABLE_DEBUG	GENMASK(7, 0)
> > +#define CSU_JTAG_CHAIN_WR_SETUP		GENMASK(1, 0)
> > +#define CSU_PCAP_PROG_RELEASE_PL	BIT(0)
> > +
> >   struct csu_regs {
> >   	u32 reserved0[4];
> >   	u32 multi_boot;
> > -	u32 reserved1[11];
> > +	u32 reserved1[7];
> > +	u32 jtag_chain_status_wr;
> > +	u32 jtag_chain_status;
> > +	u32 jtag_sec;
> > +	u32 jtag_dap_cfg;
> >   	u32 idcode;
> >   	u32 version;
> > +	u32 reserved2[3055];
> > +	u32 pcap_prog;
> >   };
> >   #define csu_base ((struct csu_regs *)ZYNQMP_CSU_BASEADDR)
> > diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
> > index 000a7cde8d..483f0b9ab2 100644
> > --- a/board/xilinx/zynqmp/zynqmp.c
> > +++ b/board/xilinx/zynqmp/zynqmp.c
> > @@ -358,6 +358,21 @@ static int multi_boot(void)
> >   	return multiboot;
> >   }
> > +#if defined(CONFIG_SPL_BUILD)
> > +static void restore_jtag(void)
> > +{
> > +	if (current_el() != 3)
> > +		return;
> > +
> > +	writel(CSU_JTAG_SEC_GATE_DISABLE, &csu_base->jtag_sec);
> > +	writel(CSU_JTAG_DAP_ENABLE_DEBUG, &csu_base->jtag_dap_cfg);
> > +	writel(CSU_JTAG_CHAIN_WR_SETUP, &csu_base->jtag_chain_status_wr);
> > +	writel(CRLAPB_DBG_LPD_CTRL_SETUP_CLK, &crlapb_base->dbg_lpd_ctrl);
> > +	writel(CRLAPB_RST_LPD_DBG_RESET, &crlapb_base->rst_lpd_dbg);
> > +	writel(CSU_PCAP_PROG_RELEASE_PL, &csu_base->pcap_prog);
> > +}
> > +#endif
> > +
> >   #define PS_SYSMON_ANALOG_BUS_VAL	0x3210
> >   #define PS_SYSMON_ANALOG_BUS_REG	0xFFA50914
> > @@ -377,11 +392,14 @@ int board_init(void)
> >   		zynqmp_pmufw_load_config_object(zynqmp_pm_cfg_obj,
> >   						zynqmp_pm_cfg_obj_size);
> >   	printf("Silicon version:\t%d\n", zynqmp_get_silicon_version());
> > +
> > +	/* the CSU disables the JTAG interface when secure boot is enabled */
> > +	if (CONFIG_IS_ENABLED(SPL_ZYNQMP_RESTORE_JTAG))
> > +		restore_jtag();
> >   #else
> >   	if (CONFIG_IS_ENABLED(DM_I2C) && CONFIG_IS_ENABLED(I2C_EEPROM))
> >   		xilinx_read_eeprom();
> >   #endif
> > -
> 
> Unrelated.

?
checkpatch will fail if we leave two carriage returns

> 
> >   	printf("EL Level:\tEL%d\n", current_el());
> >   	/* Bug in ROM sets wrong value in this register */
> > 
> 
> M