linux/Documentation/arm/samsung/bootloader-interface.rst
Mauro Carvalho Chehab dc7a12bdfc docs: arm: convert docs to ReST and rename to *.rst
Converts ARM the text files to ReST, preparing them to be an
architecture book.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-07-15 09:20:24 -03:00

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3.7 KiB
ReStructuredText

==========================================================
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, mcpm_entry_point 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
0x28 0x0 or last value during resume (Exynos542x) System suspend
============= ============================================ ==================
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, suspend
0x0800 mcpm_entry_point (Exynos542x with MCPM) AFTR, suspend
0x0804 0xfcba0d10 (Magic cookie) AFTR
0x0804 0x00000bad (Magic cookie) System suspend
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 Secondary CPU boot up indicator
on Exynos3250 and Exynos542x
============= =============================== ===============================
4. Glossary
AFTR - ARM Off Top Running, a low power mode, Cortex cores and many other
modules are power gated, except the TOP modules
MCPM - Multi-Cluster Power Management