Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1 Interface between kernel and boot loaders on Exynos boards
2 ==========================================================
3
4Author: Krzysztof Kozlowski
5Date : 6 June 2015
6
7The document tries to describe currently used interface between Linux kernel
8and boot loaders on Samsung Exynos based boards. This is not a definition
9of interface but rather a description of existing state, a reference
10for information purpose only.
11
12In the document "boot loader" means any of following: U-boot, proprietary
13SBOOT or any other firmware for ARMv7 and ARMv8 initializing the board before
14executing kernel.
15
16
171. Non-Secure mode
18Address: sysram_ns_base_addr
19Offset Value Purpose
20=============================================================================
210x08 exynos_cpu_resume_ns System suspend
220x0c 0x00000bad (Magic cookie) System suspend
230x1c exynos4_secondary_startup Secondary CPU boot
240x1c + 4*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot
250x20 0xfcba0d10 (Magic cookie) AFTR
260x24 exynos_cpu_resume_ns AFTR
270x28 + 4*cpu 0x8 (Magic cookie, Exynos3250) AFTR
28
29
302. Secure mode
31Address: sysram_base_addr
32Offset Value Purpose
33=============================================================================
340x00 exynos4_secondary_startup Secondary CPU boot
350x04 exynos4_secondary_startup (Exynos542x) Secondary CPU boot
364*cpu exynos4_secondary_startup (Exynos4412) Secondary CPU boot
370x20 exynos_cpu_resume (Exynos4210 r1.0) AFTR
380x24 0xfcba0d10 (Magic cookie, Exynos4210 r1.0) AFTR
39
40Address: pmu_base_addr
41Offset Value Purpose
42=============================================================================
430x0800 exynos_cpu_resume AFTR
440x0814 exynos4_secondary_startup (Exynos4210 r1.1) Secondary CPU boot
450x0818 0xfcba0d10 (Magic cookie, Exynos4210 r1.1) AFTR
460x081C exynos_cpu_resume (Exynos4210 r1.1) AFTR
47
48
493. Other (regardless of secure/non-secure mode)
50Address: pmu_base_addr
51Offset Value Purpose
52=============================================================================
530x0908 Non-zero (only Exynos3250) Secondary CPU boot up indicator