From aec56ef4f3cf0417a28ddc0719603d54073eee09 Mon Sep 17 00:00:00 2001 From: Yong Li Date: Tue, 20 Aug 2019 16:10:03 +0800 Subject: [PATCH] Disable uart debug interface AST2500 SOC integrates a UART debug interface which can input commands to AST2500 by using simple terminal program without the assistance of CPU. For security requirements, we need to disable this feature, set SCU2C[]10 = 1 to disable it. Tested: Flash the u-boot.bin and dump SCU2C as below: md 0x1e6e202c 1e6e202c: 00200400 Signed-off-by: Yong Li Signed-off-by: Vikram Bodireddy --- arch/arm/include/asm/arch-aspeed/regs-scu.h | 1 + board/aspeed/ast-g5/ast-g5-intel.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/arch/arm/include/asm/arch-aspeed/regs-scu.h b/arch/arm/include/asm/arch-aspeed/regs-scu.h index a2c9549fc6..1bdb1d8574 100644 --- a/arch/arm/include/asm/arch-aspeed/regs-scu.h +++ b/arch/arm/include/asm/arch-aspeed/regs-scu.h @@ -468,6 +468,7 @@ #define SCU_MISC_DIV13_EN (0x1 << 12) #define SCU_MISC_DEBUG_UART (0x1 << 10) #define SCU_MISC_Y_CLK_INVERT (0x1 << 11) +#define SCU_MISC_UART_DEBUG_DIS (0x1 << 10) #define SCU_MISC_OUT_DELAY (0x1 << 9) #define SCU_MISC_PCI_TO_AHB_DIS (0x1 << 8) #define SCU_MISC_2D_CRT_EN (0x1 << 7) diff --git a/board/aspeed/ast-g5/ast-g5-intel.c b/board/aspeed/ast-g5/ast-g5-intel.c index 12216922ac..e05a6da468 100644 --- a/board/aspeed/ast-g5/ast-g5-intel.c +++ b/board/aspeed/ast-g5/ast-g5-intel.c @@ -589,6 +589,10 @@ extern void espi_init(void); extern void kcs_init(void); void ast_g5_intel(void) { + /* Disable uart port debug function */ + ast_scu_write(ast_scu_read(AST_SCU_MISC1_CTRL) | + SCU_MISC_UART_DEBUG_DIS, AST_SCU_MISC1_CTRL); + uart_init(); pwm_init(); gpio_init(gpio_table, ARRAY_SIZE(gpio_table));