summaryrefslogtreecommitdiff
path: root/Documentation/arm64/booting.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/arm64/booting.txt')
-rw-r--r--Documentation/arm64/booting.txt18
1 files changed, 16 insertions, 2 deletions
diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt
index 7d9d3c2286b2..701d39d3171a 100644
--- a/Documentation/arm64/booting.txt
+++ b/Documentation/arm64/booting.txt
@@ -104,7 +104,12 @@ Header notes:
- The flags field (introduced in v3.17) is a little-endian 64-bit field
composed as follows:
Bit 0: Kernel endianness. 1 if BE, 0 if LE.
- Bits 1-63: Reserved.
+ Bit 1-2: Kernel Page size.
+ 0 - Unspecified.
+ 1 - 4K
+ 2 - 16K
+ 3 - 64K
+ Bits 3-63: Reserved.
- When image_size is zero, a bootloader should attempt to keep as much
memory as possible free for use by the kernel immediately after the
@@ -173,13 +178,22 @@ Before jumping into the kernel, the following conditions must be met:
the kernel image will be entered must be initialised by software at a
higher exception level to prevent execution in an UNKNOWN state.
- For systems with a GICv3 interrupt controller:
+ For systems with a GICv3 interrupt controller to be used in v3 mode:
- If EL3 is present:
ICC_SRE_EL3.Enable (bit 3) must be initialiased to 0b1.
ICC_SRE_EL3.SRE (bit 0) must be initialised to 0b1.
- If the kernel is entered at EL1:
ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
+ - The DT or ACPI tables must describe a GICv3 interrupt controller.
+
+ For systems with a GICv3 interrupt controller to be used in
+ compatibility (v2) mode:
+ - If EL3 is present:
+ ICC_SRE_EL3.SRE (bit 0) must be initialised to 0b0.
+ - If the kernel is entered at EL1:
+ ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b0.
+ - The DT or ACPI tables must describe a GICv2 interrupt controller.
The requirements described above for CPU mode, caches, MMUs, architected
timers, coherency and system registers apply to all CPUs. All CPUs must