diff options
Diffstat (limited to 'arch/arm/cpu/armv7/exynos/sec_boot.S')
| -rw-r--r-- | arch/arm/cpu/armv7/exynos/sec_boot.S | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/exynos/sec_boot.S b/arch/arm/cpu/armv7/exynos/sec_boot.S new file mode 100644 index 0000000000..dfc3455929 --- /dev/null +++ b/arch/arm/cpu/armv7/exynos/sec_boot.S @@ -0,0 +1,128 @@ +/* + * Copyright (C) 2013 Samsung Electronics + * Akshay Saraswat <akshay.s@samsung.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <config.h> +#include <asm/arch/cpu.h> + + .globl relocate_wait_code +relocate_wait_code: + adr r0, code_base @ r0: source address (start) + adr r1, code_end @ r1: source address (end) + ldr r2, =0x02073000 @ r2: target address +1: + ldmia r0!, {r3-r6} + stmia r2!, {r3-r6} + cmp r0, r1 + blt 1b + b code_end + .ltorg +/* + * Secondary core waits here until Primary wake it up. + * Below code is copied to CONFIG_EXYNOS_RELOCATE_CODE_BASE. + * This is a workaround code which is supposed to act as a + * substitute/supplement to the iROM code. + * + * This workaround code is relocated to the address 0x02073000 + * because that comes out to be the last 4KB of the iRAM + * (Base Address - 0x02020000, Limit Address - 0x020740000). + * + * U-boot and kernel are aware of this code and flags by the simple + * fact that we are implementing a workaround in the last 4KB + * of the iRAM and we have already defined these flag and address + * values in both kernel and U-boot for our use. + */ +code_base: + b 1f +/* + * These addresses are being used as flags in u-boot and kernel. + * + * Jump address for resume and flag to check for resume/reset: + * Resume address - 0x2073008 + * Resume flag - 0x207300C + * + * Jump address for cluster switching: + * Switch address - 0x2073018 + * + * Jump address for core hotplug: + * Hotplug address - 0x207301C + * + * Jump address for C2 state (Reserved for future not being used right now): + * C2 address - 0x2073024 + * + * Managed per core status for the active cluster: + * CPU0 state - 0x2073028 + * CPU1 state - 0x207302C + * CPU2 state - 0x2073030 + * CPU3 state - 0x2073034 + * + * Managed per core GIC status for the active cluster: + * CPU0 gic state - 0x2073038 + * CPU1 gic state - 0x207303C + * CPU2 gic state - 0x2073040 + * CPU3 gic state - 0x2073044 + * + * Logic of the code: + * Step-1: Read current CPU status. + * Step-2: If it's a resume then continue, else jump to step 4. + * Step-3: Clear inform1 PMU register and jump to inform0 value. + * Step-4: If it's a switch, C2 or reset, get the hotplug address. + * Step-5: If address is not available, enter WFE. + * Step-6: If address is available, jump to that address. + */ + nop @ for backward compatibility + .word 0x0 @ REG0: RESUME_ADDR + .word 0x0 @ REG1: RESUME_FLAG + .word 0x0 @ REG2 + .word 0x0 @ REG3 +_switch_addr: + .word 0x0 @ REG4: SWITCH_ADDR +_hotplug_addr: + .word 0x0 @ REG5: CPU1_BOOT_REG + .word 0x0 @ REG6 +_c2_addr: + .word 0x0 @ REG7: REG_C2_ADDR +_cpu_state: + .word 0x1 @ CPU0_STATE : RESET + .word 0x2 @ CPU1_STATE : SECONDARY RESET + .word 0x2 @ CPU2_STATE : SECONDARY RESET + .word 0x2 @ CPU3_STATE : SECONDARY RESET +_gic_state: + .word 0x0 @ CPU0 - GICD_IGROUPR0 + .word 0x0 @ CPU1 - GICD_IGROUPR0 + .word 0x0 @ CPU2 - GICD_IGROUPR0 + .word 0x0 @ CPU3 - GICD_IGROUPR0 +1: + adr r0, _cpu_state + mrc p15, 0, r7, c0, c0, 5 @ read MPIDR + and r7, r7, #0xf @ r7 = cpu id +/* Read the current cpu state */ + ldr r10, [r0, r7, lsl #2] +svc_entry: + tst r10, #(1 << 4) + adrne r0, _switch_addr + bne wait_for_addr +/* Clear INFORM1 */ + ldr r0, =(0x10040000 + 0x804) + ldr r1, [r0] + cmp r1, #0x0 + movne r1, #0x0 + strne r1, [r0] +/* Get INFORM0 */ + ldrne r1, =(0x10040000 + 0x800) + ldrne pc, [r1] + tst r10, #(1 << 0) + ldrne pc, =0x23e00000 + adr r0, _hotplug_addr +wait_for_addr: + ldr r1, [r0] + cmp r1, #0x0 + bxne r1 + wfe + b wait_for_addr + .ltorg +code_end: + mov pc, lr |
