Linux-libre 4.2-gnu

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+      Interface between kernel and boot loaders on Exynos boards
+      ==========================================================
+
+Author: Krzysztof Kozlowski
+Date  : 6 June 2015
+
+The document tries to describe currently used interface between Linux kernel
+and boot loaders on Samsung Exynos based boards. This is not a definition
+of interface but rather a description of existing state, a reference
+for information purpose only.
+
+In the document "boot loader" means any of following: U-boot, proprietary
+SBOOT or any other firmware for ARMv7 and ARMv8 initializing the board before
+executing kernel.
+
+
+1. Non-Secure mode
+Address:      sysram_ns_base_addr
+Offset        Value                                        Purpose
+=============================================================================
+0x08          exynos_cpu_resume_ns                         System suspend
+0x0c          0x00000bad (Magic cookie)                    System suspend
+0x1c          exynos4_secondary_startup                    Secondary CPU boot
+0x1c + 4*cpu  exynos4_secondary_startup (Exynos4412)       Secondary CPU boot
+0x20          0xfcba0d10 (Magic cookie)                    AFTR
+0x24          exynos_cpu_resume_ns                         AFTR
+0x28 + 4*cpu  0x8 (Magic cookie, Exynos3250)               AFTR
+
+
+2. Secure mode
+Address:      sysram_base_addr
+Offset        Value                                        Purpose
+=============================================================================
+0x00          exynos4_secondary_startup                    Secondary CPU boot
+0x04          exynos4_secondary_startup (Exynos542x)       Secondary CPU boot
+4*cpu         exynos4_secondary_startup (Exynos4412)       Secondary CPU boot
+0x20          exynos_cpu_resume (Exynos4210 r1.0)          AFTR
+0x24          0xfcba0d10 (Magic cookie, Exynos4210 r1.0)   AFTR
+
+Address:      pmu_base_addr
+Offset        Value                                        Purpose
+=============================================================================
+0x0800        exynos_cpu_resume                            AFTR
+0x0814        exynos4_secondary_startup (Exynos4210 r1.1)  Secondary CPU boot
+0x0818        0xfcba0d10 (Magic cookie, Exynos4210 r1.1)   AFTR
+0x081C        exynos_cpu_resume (Exynos4210 r1.1)          AFTR
+
+
+3. Other (regardless of secure/non-secure mode)
+Address:      pmu_base_addr
+Offset        Value                           Purpose
+=============================================================================
+0x0908        Non-zero (only Exynos3250)      Secondary CPU boot up indicator