Reboot mode is written to SAR memory before reboot in the form of a string.
This mechanism is supported on OMAP4 by various TI kernels.
It is up to each board to make use of this mechanism or not.
Signed-off-by: Paul Kocialkowski contact@paulk.fr --- arch/arm/cpu/armv7/omap4/boot.c | 41 ++++++++++++++++++++++++++++++++++ arch/arm/include/asm/arch-omap4/omap.h | 8 +++++++ 2 files changed, 49 insertions(+)
diff --git a/arch/arm/cpu/armv7/omap4/boot.c b/arch/arm/cpu/armv7/omap4/boot.c index 4b5aa77..bae49f4 100644 --- a/arch/arm/cpu/armv7/omap4/boot.c +++ b/arch/arm/cpu/armv7/omap4/boot.c @@ -58,3 +58,44 @@ u32 omap_sys_boot_device(void)
return boot_devices[sys_boot]; } + +int omap_reboot_mode(char *mode, unsigned int length) +{ + unsigned int limit; + unsigned int i; + + if (length < 2) + return -1; + + limit = (length < OMAP_REBOOT_REASON_SIZE) ? length : + OMAP_REBOOT_REASON_SIZE; + + for (i = 0; i < (limit - 1); i++) + mode[i] = readb((u8 *)(OMAP44XX_SAR_RAM_BASE + + OMAP_REBOOT_REASON_OFFSET + i)); + + mode[i] = '\0'; + + return 0; +} + +int omap_reboot_mode_clear(void) +{ + writeb(0, (u8 *)(OMAP44XX_SAR_RAM_BASE + OMAP_REBOOT_REASON_OFFSET)); + + return 0; +} + +int omap_reboot_mode_store(char *mode) +{ + unsigned int i; + + for (i = 0; i < (OMAP_REBOOT_REASON_SIZE - 1) && mode[i] != '\0'; i++) + writeb(mode[i], (u8 *)(OMAP44XX_SAR_RAM_BASE + + OMAP_REBOOT_REASON_OFFSET + i)); + + writeb('\0', (u8 *)(OMAP44XX_SAR_RAM_BASE + + OMAP_REBOOT_REASON_OFFSET + i)); + + return 0; +} diff --git a/arch/arm/include/asm/arch-omap4/omap.h b/arch/arm/include/asm/arch-omap4/omap.h index 4712722..5ccda6e 100644 --- a/arch/arm/include/asm/arch-omap4/omap.h +++ b/arch/arm/include/asm/arch-omap4/omap.h @@ -120,6 +120,10 @@ struct s32ktimer { /* ABB tranxdone mask */ #define OMAP_ABB_MPU_TXDONE_MASK (0x1 << 7)
+#define OMAP44XX_SAR_RAM_BASE 0x4a326000 +#define OMAP_REBOOT_REASON_OFFSET 0xA0C +#define OMAP_REBOOT_REASON_SIZE 0x0F + /* Boot parameters */ #ifndef __ASSEMBLY__ struct omap_boot_parameters { @@ -129,6 +133,10 @@ struct omap_boot_parameters { unsigned char reset_reason; unsigned char ch_flags; }; + +int omap_reboot_mode(char *mode, unsigned int length); +int omap_reboot_mode_clear(void); +int omap_reboot_mode_store(char *mode); #endif
#endif