0001 ==========================================================
0002 Interface between kernel and boot loaders on Exynos boards
0003 ==========================================================
0004
0005 Author: Krzysztof Kozlowski
0006
0007 Date : 6 June 2015
0008
0009 The document tries to describe currently used interface between Linux kernel
0010 and boot loaders on Samsung Exynos based boards. This is not a definition
0011 of interface but rather a description of existing state, a reference
0012 for information purpose only.
0013
0014 In the document "boot loader" means any of following: U-boot, proprietary
0015 SBOOT or any other firmware for ARMv7 and ARMv8 initializing the board before
0016 executing kernel.
0017
0018
0019 1. Non-Secure mode
0020
0021 Address: sysram_ns_base_addr
0022
0023 ============= ============================================ ==================
0024 Offset Value Purpose
0025 ============= ============================================ ==================
0026 0x08 exynos_cpu_resume_ns, mcpm_entry_point System suspend
0027 0x0c 0x00000bad (Magic cookie) System suspend
0028 0x1c exynos4_secondary_startup Secondary CPU boot
0029 0x1c + 4*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot
0030 0x20 0xfcba0d10 (Magic cookie) AFTR
0031 0x24 exynos_cpu_resume_ns AFTR
0032 0x28 + 4*cpu 0x8 (Magic cookie, Exynos3250) AFTR
0033 0x28 0x0 or last value during resume (Exynos542x) System suspend
0034 ============= ============================================ ==================
0035
0036
0037 2. Secure mode
0038
0039 Address: sysram_base_addr
0040
0041 ============= ============================================ ==================
0042 Offset Value Purpose
0043 ============= ============================================ ==================
0044 0x00 exynos4_secondary_startup Secondary CPU boot
0045 0x04 exynos4_secondary_startup (Exynos542x) Secondary CPU boot
0046 4*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot
0047 0x20 exynos_cpu_resume (Exynos4210 r1.0) AFTR
0048 0x24 0xfcba0d10 (Magic cookie, Exynos4210 r1.0) AFTR
0049 ============= ============================================ ==================
0050
0051 Address: pmu_base_addr
0052
0053 ============= ============================================ ==================
0054 Offset Value Purpose
0055 ============= ============================================ ==================
0056 0x0800 exynos_cpu_resume AFTR, suspend
0057 0x0800 mcpm_entry_point (Exynos542x with MCPM) AFTR, suspend
0058 0x0804 0xfcba0d10 (Magic cookie) AFTR
0059 0x0804 0x00000bad (Magic cookie) System suspend
0060 0x0814 exynos4_secondary_startup (Exynos4210 r1.1) Secondary CPU boot
0061 0x0818 0xfcba0d10 (Magic cookie, Exynos4210 r1.1) AFTR
0062 0x081C exynos_cpu_resume (Exynos4210 r1.1) AFTR
0063 ============= ============================================ ==================
0064
0065 3. Other (regardless of secure/non-secure mode)
0066
0067 Address: pmu_base_addr
0068
0069 ============= =============================== ===============================
0070 Offset Value Purpose
0071 ============= =============================== ===============================
0072 0x0908 Non-zero Secondary CPU boot up indicator
0073 on Exynos3250 and Exynos542x
0074 ============= =============================== ===============================
0075
0076
0077 4. Glossary
0078
0079 AFTR - ARM Off Top Running, a low power mode, Cortex cores and many other
0080 modules are power gated, except the TOP modules
0081 MCPM - Multi-Cluster Power Management
