From 9b076436182dd6113e67e19f7b6080dc77c57141 Mon Sep 17 00:00:00 2001 From: Marcin Juszkiewicz Date: Wed, 10 Jan 2024 17:57:26 +0100 Subject: [PATCH] docs(qemu-sbsa): describe what we get from QEMU QEMU provides us with minimal information about hardware platform using minimalistic DeviceTree. This is not a Linux DeviceTree. It is not even a firmware DeviceTree. Change-Id: I7b6cc5f53a4f78a9ed69bc7fc2fa1a69ea65428d Signed-off-by: Marcin Juszkiewicz --- plat/qemu/qemu_sbsa/sbsa_sip_svc.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/plat/qemu/qemu_sbsa/sbsa_sip_svc.c b/plat/qemu/qemu_sbsa/sbsa_sip_svc.c index 31c083f41..da40c78dd 100644 --- a/plat/qemu/qemu_sbsa/sbsa_sip_svc.c +++ b/plat/qemu/qemu_sbsa/sbsa_sip_svc.c @@ -47,6 +47,20 @@ void sbsa_set_gic_bases(const uintptr_t gicd_base, const uintptr_t gicr_base); uintptr_t sbsa_get_gicd(void); uintptr_t sbsa_get_gicr(void); +/* + * QEMU provides us with minimal information about hardware platform using + * minimalistic DeviceTree. This is not a Linux DeviceTree. It is not even + * a firmware DeviceTree. + * + * It is information passed from QEMU to describe the information a hardware + * platform would have other mechanisms to discover at runtime, that are + * affected by the QEMU command line. + * + * Ultimately this device tree will be replaced by IPC calls to an emulated SCP. + * And when we do that, we won't then have to rewrite Normal world firmware to + * cope. + */ + void read_cpuinfo_from_dt(void *dtb) { int node;