1 Interface between kernel and boot loaders on Exynos boards
2 ==========================================================
4 Author: Krzysztof Kozlowski
7 The document tries to describe currently used interface between Linux kernel
8 and boot loaders on Samsung Exynos based boards. This is not a definition
9 of interface but rather a description of existing state, a reference
10 for information purpose only.
12 In the document "boot loader" means any of following: U-boot, proprietary
13 SBOOT or any other firmware for ARMv7 and ARMv8 initializing the board before
19 Address: sysram_ns_base_addr
21 =============================================================================
22 0x08 exynos_cpu_resume_ns, mcpm_entry_point System suspend
23 0x0c 0x00000bad (Magic cookie) System suspend
24 0x1c exynos4_secondary_startup Secondary CPU boot
25 0x1c + 4*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot
26 0x20 0xfcba0d10 (Magic cookie) AFTR
27 0x24 exynos_cpu_resume_ns AFTR
28 0x28 + 4*cpu 0x8 (Magic cookie, Exynos3250) AFTR
29 0x28 0x0 or last value during resume (Exynos542x) System suspend
34 Address: sysram_base_addr
36 =============================================================================
37 0x00 exynos4_secondary_startup Secondary CPU boot
38 0x04 exynos4_secondary_startup (Exynos542x) Secondary CPU boot
39 4*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot
40 0x20 exynos_cpu_resume (Exynos4210 r1.0) AFTR
41 0x24 0xfcba0d10 (Magic cookie, Exynos4210 r1.0) AFTR
43 Address: pmu_base_addr
45 =============================================================================
46 0x0800 exynos_cpu_resume AFTR, suspend
47 0x0800 mcpm_entry_point (Exynos542x with MCPM) AFTR, suspend
48 0x0804 0xfcba0d10 (Magic cookie) AFTR
49 0x0804 0x00000bad (Magic cookie) System suspend
50 0x0814 exynos4_secondary_startup (Exynos4210 r1.1) Secondary CPU boot
51 0x0818 0xfcba0d10 (Magic cookie, Exynos4210 r1.1) AFTR
52 0x081C exynos_cpu_resume (Exynos4210 r1.1) AFTR
55 3. Other (regardless of secure/non-secure mode)
57 Address: pmu_base_addr
59 =============================================================================
60 0x0908 Non-zero Secondary CPU boot up indicator
61 on Exynos3250 and Exynos542x
66 AFTR - ARM Off Top Running, a low power mode, Cortex cores and many other
67 modules are power gated, except the TOP modules
68 MCPM - Multi-Cluster Power Management