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Diffstat (limited to '')
| -rw-r--r-- | plat/qti/msm8916/aarch64/msm8916_helpers.S | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/plat/qti/msm8916/aarch64/msm8916_helpers.S b/plat/qti/msm8916/aarch64/msm8916_helpers.S new file mode 100644 index 0000000..dad9968 --- /dev/null +++ b/plat/qti/msm8916/aarch64/msm8916_helpers.S @@ -0,0 +1,164 @@ +/* + * Copyright (c) 2021, Stephan Gerhold <stephan@gerhold.net> + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch.h> +#include <asm_macros.S> + +#include <msm8916_mmap.h> + +#define APCS_TCM_START_ADDR 0x10 +#define APCS_TCM_REDIRECT_EN_0 BIT_32(0) + + .globl plat_crash_console_init + .globl plat_crash_console_putc + .globl plat_crash_console_flush + .globl plat_panic_handler + .globl plat_my_core_pos + .globl plat_get_my_entrypoint + .globl plat_reset_handler + .globl platform_mem_init + .globl msm8916_entry_point + + /* ------------------------------------------------- + * int plat_crash_console_init(void) + * Initialize the crash console. + * Out: x0 - 1 on success, 0 on error + * Clobber list : x0 - x4 + * ------------------------------------------------- + */ +func plat_crash_console_init + mov x1, #BLSP_UART2_BASE + + /* + * If the non-secure world has been actively using the UART there might + * be still some characters left to be sent in the FIFO. In that case, + * resetting the transmitter too early might cause all output to become + * corrupted. To avoid that, try to flush (wait until FIFO empty) first. + */ + mov x4, lr + bl console_uartdm_core_flush + mov lr, x4 + + mov x0, #1 + b console_uartdm_core_init +endfunc plat_crash_console_init + + /* ------------------------------------------------- + * int plat_crash_console_putc(int c) + * Print a character on the crash console. + * In : w0 - character to be printed + * Out: w0 - printed character on success + * Clobber list : x1, x2 + * ------------------------------------------------- + */ +func plat_crash_console_putc + mov x1, #BLSP_UART2_BASE + b console_uartdm_core_putc +endfunc plat_crash_console_putc + + /* ------------------------------------------------- + * void plat_crash_console_flush(void) + * Force a write of all buffered data that has not + * been output. + * Clobber list : x1, x2 + * ------------------------------------------------- + */ +func plat_crash_console_flush + mov x1, #BLSP_UART2_BASE + b console_uartdm_core_flush +endfunc plat_crash_console_flush + + /* ------------------------------------------------- + * void plat_panic_handler(void) __dead + * Called when an unrecoverable error occurs. + * ------------------------------------------------- + */ +func plat_panic_handler + /* Try to shutdown/reset */ + mov_imm x0, MPM_PS_HOLD + str wzr, [x0] +1: b 1b +endfunc plat_panic_handler + + /* ------------------------------------------------- + * unsigned int plat_my_core_pos(void) + * Out: x0 - index of the calling CPU + * ------------------------------------------------- + */ +func plat_my_core_pos + /* There is just a single cluster so this is very simple */ + mrs x0, mpidr_el1 + and x0, x0, #MPIDR_CPU_MASK + ret +endfunc plat_my_core_pos + + /* ------------------------------------------------- + * uintptr_t plat_get_my_entrypoint(void) + * Distinguish cold and warm boot and return warm boot + * entry address if available. + * Out: x0 - warm boot entry point or 0 on cold boot + * ------------------------------------------------- + */ +func plat_get_my_entrypoint + ldr x0, msm8916_entry_point + ret +endfunc plat_get_my_entrypoint + + /* ------------------------------------------------- + * void plat_reset_handler(void) + * Perform additional initialization after reset. + * Clobber list : x0 - x18, x30 + * ------------------------------------------------- + */ +func plat_reset_handler + /* + * Check if the CPU is running at the correct address. + * During cold boot the CPU enters here at the wrong address + * using the "boot remapper". (It remaps the BL31_BASE to + * the CPU reset address 0x0). + */ + mov x0, #BL31_BASE + adr x1, bl31_entrypoint + cmp x0, x1 + b.ne _remapped_cold_boot + /* Already running at correct address, just return directly */ + ret + +_remapped_cold_boot: + /* + * The previous boot stage seems to use the L2 cache as TCM. + * Disable the TCM redirect before enabling caches to avoid + * strange crashes. + */ + mov x2, #APCS_CFG + ldr w3, [x2, #APCS_TCM_START_ADDR] + and w3, w3, #~APCS_TCM_REDIRECT_EN_0 + str w3, [x2, #APCS_TCM_START_ADDR] + + /* Enter BL31 again at the real address */ + br x0 +endfunc plat_reset_handler + + /* ------------------------------------------------- + * void platform_mem_init(void) + * Performs additional memory initialization early + * in the boot process. + * ------------------------------------------------- + */ +func platform_mem_init + /* Nothing to do here, all memory is already initialized */ + ret +endfunc platform_mem_init + + .data + .align 3 + + /* ------------------------------------------------- + * Warm boot entry point for CPU. Set by PSCI code. + * ------------------------------------------------- + */ +msm8916_entry_point: + .quad 0 |