A-A+
coreboot学习8：ramstage阶段之资源分配流程
设备枚举后就是资源分配了，在dev_configure函数中完成，代码如下：
void dev_configure(void)
{
struct resource *res;
struct device *root;
struct device *child;
set_vga_bridge_bits();
printk(BIOS_INFO, "Allocating resources...\n");
root = &dev_root; // 根设备
/*
* Each domain should create resources which contain the entire address
* space for IO, MEM, and PREFMEM resources in the domain. The
* allocation of device resources will be done from this address space.
*/
/* Read the resources for the entire tree. */
// 先读一次
printk(BIOS_INFO, "Reading resources...\n");
read_resources(root->link_list);
printk(BIOS_INFO, "Done reading resources.\n");
// 打印设备树的资源
print_resource_tree(root, BIOS_SPEW, "After reading.");
/* Compute resources for all domains. */
// 计算资源
for (child = root->link_list->children; child; child = child->sibling) {
if (!(child->path.type == DEVICE_PATH_DOMAIN))
continue;
post_log_path(child);
for (res = child->resource_list; res; res = res->next) {
if (res->flags & IORESOURCE_FIXED)
continue;
if (res->flags & IORESOURCE_MEM) {
compute_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM);
continue;
}
if (res->flags & IORESOURCE_IO) {
compute_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_IO);
continue;
}
}
}
/* For all domains. */
for (child = root->link_list->children; child; child=child->sibling)
if (child->path.type == DEVICE_PATH_DOMAIN)
avoid_fixed_resources(child); // 此函数作用? 感觉是对范围的限制
/* Store the computed resource allocations into device registers ... */
printk(BIOS_INFO, "Setting resources...\n");
for (child = root->link_list->children; child; child = child->sibling) {
if (!(child->path.type == DEVICE_PATH_DOMAIN))
continue;
post_log_path(child);
// 分mem和io两种资源
for (res = child->resource_list; res; res = res->next) {
if (res->flags & IORESOURCE_FIXED)
continue;
if (res->flags & IORESOURCE_MEM) {
allocate_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_MEM);
continue;
}
if (res->flags & IORESOURCE_IO) {
allocate_resources(child->link_list,
res, IORESOURCE_TYPE_MASK, IORESOURCE_IO);
continue;
}
}
}
assign_resources(root->link_list);
printk(BIOS_INFO, "Done setting resources.\n");
print_resource_tree(root, BIOS_SPEW, "After assigning values.");
printk(BIOS_INFO, "Done allocating resources.\n");
}
从该函数看出大概有几个步骤：
1、先读一次设备树上的资源，并打印出来。
2、计算资源，compute_resources。
3、对资源范围做限制，avoid_fixed_resources。
4、申请资源，allocate_resources。
5、分配资源，assign_resources。
6、打印分配好的资源(注：此时设备树的资源有部分是第1步骤打印的不同)。
根据代码整理的流程图如下：
(此处留空)
附上此过程的打印信息：
[LL DEBUG]: in bs_dev_resources()... found VGA at PCI: 00:02.0 Setting up VGA for PCI: 00:02.0 Setting PCI_BRIDGE_CTL_VGA for bridge DOMAIN: 0000 Setting PCI_BRIDGE_CTL_VGA for bridge Root Device Allocating resources... Reading resources... Root Device read_resources bus 0 link: 0 CPU_CLUSTER: 0 read_resources bus 0 link: 0 CPU_CLUSTER: 0 read_resources bus 0 link: 0 done QEMU: 8 files in fw_cfg QEMU: etc/boot-fail-wait [size=4] QEMU: etc/e820 [size=20] QEMU: genroms/kvmvapic.bin [size=9216] QEMU: etc/system-states [size=6] QEMU: bootorder [size=0] QEMU: etc/acpi/tables [size=8192] QEMU: etc/table-loader [size=4096] QEMU: etc/acpi/rsdp [size=36] QEMU: e820/ram: 0x00000000 +0x08000000 QEMU: reserve ioports 0x0510-0x0511 [firmware-config] QEMU: reserve ioports 0x5658-0x5658 [vmware-port] QEMU: reserve ioports 0xae00-0xae0f [pci-hotplug] QEMU: reserve ioports 0xaf00-0xaf1f [cpu-hotplug] QEMU: reserve ioports 0xafe0-0xafe3 [piix4-gpe0] DOMAIN: 0000 read_resources bus 0 link: 0 DOMAIN: 0000 read_resources bus 0 link: 0 done Root Device read_resources bus 0 link: 0 done Done reading resources. Show resources in subtree (Root Device)...After reading. Root Device child on link 0 CPU_CLUSTER: 0 CPU_CLUSTER: 0 child on link 0 APIC: 00 APIC: 00 DOMAIN: 0000 child on link 0 PCI: 00:00.0 DOMAIN: 0000 resource base 0 size 0 align 0 gran 0 limit ffff flags 40040100 index 10000000 DOMAIN: 0000 resource base 0 size 0 align 0 gran 0 limit ffffffff flags 40040200 index 10000100 DOMAIN: 0000 resource base 0 size a0000 align 0 gran 0 limit 0 flags e0004200 index a DOMAIN: 0000 resource base c0000 size 7f40000 align 0 gran 0 limit 0 flags e0004200 index b DOMAIN: 0000 resource base 510 size 2 align 0 gran 0 limit ffff flags e0000100 index c DOMAIN: 0000 resource base 5658 size 1 align 0 gran 0 limit ffff flags e0000100 index d DOMAIN: 0000 resource base ae00 size 10 align 0 gran 0 limit ffff flags e0000100 index e DOMAIN: 0000 resource base af00 size 20 align 0 gran 0 limit ffff flags e0000100 index f DOMAIN: 0000 resource base afe0 size 4 align 0 gran 0 limit ffff flags e0000100 index 10 DOMAIN: 0000 resource base fec00000 size 100000 align 0 gran 0 limit ffffffff flags e0000200 index 2 DOMAIN: 0000 resource base fee00000 size 10000 align 0 gran 0 limit ffffffff flags e0000200 index 3 PCI: 00:00.0 PCI: 00:01.0 PCI: 00:01.0 resource base 0 size 1000 align 0 gran 0 limit ffff flags c0000100 index 1 PCI: 00:01.0 resource base ff800000 size 800000 align 0 gran 0 limit 0 flags d0000200 index 2 PCI: 00:01.1 PCI: 00:01.1 resource base 0 size 10 align 4 gran 4 limit ffff flags 100 index 20 PCI: 00:01.3 PCI: 00:01.3 resource base e400 size 40 align 0 gran 0 limit ffff flags d0000100 index 1 PCI: 00:01.3 resource base f00 size 10 align 0 gran 0 limit ffff flags d0000100 index 2 PCI: 00:02.0 PCI: 00:02.0 resource base 0 size 2000000 align 25 gran 25 limit ffffffff flags 1200 index 10 PCI: 00:02.0 resource base 0 size 1000 align 12 gran 12 limit ffffffff flags 200 index 14 PCI: 00:02.0 resource base 0 size 10000 align 16 gran 16 limit ffffffff flags 2200 index 30 PCI: 00:03.0 PCI: 00:03.0 resource base 0 size 20000 align 17 gran 17 limit ffffffff flags 200 index 10 PCI: 00:03.0 resource base 0 size 40 align 6 gran 6 limit ffff flags 100 index 14 PCI: 00:03.0 resource base 0 size 40000 align 18 gran 18 limit ffffffff flags 2200 index 30 DOMAIN: 0000 io: base: 0 size: 0 align: 0 gran: 0 limit: ffff PCI: 00:03.0 14 * [0x0 - 0x3f] io PCI: 00:01.1 20 * [0x40 - 0x4f] io DOMAIN: 0000 io: base: 50 size: 50 align: 6 gran: 0 limit: ffff done DOMAIN: 0000 mem: base: 0 size: 0 align: 0 gran: 0 limit: ffffffff PCI: 00:02.0 10 * [0x0 - 0x1ffffff] prefmem PCI: 00:03.0 30 * [0x2000000 - 0x203ffff] mem PCI: 00:03.0 10 * [0x2040000 - 0x205ffff] mem PCI: 00:02.0 30 * [0x2060000 - 0x206ffff] mem PCI: 00:02.0 14 * [0x2070000 - 0x2070fff] mem DOMAIN: 0000 mem: base: 2071000 size: 2071000 align: 25 gran: 0 limit: ffffffff done avoid_fixed_resources: DOMAIN: 0000 avoid_fixed_resources:@DOMAIN: 0000 10000000 limit 0000ffff avoid_fixed_resources:@DOMAIN: 0000 10000100 limit ffffffff constrain_resources: DOMAIN: 0000 0a base 00000000 limit 0009ffff mem (fixed) constrain_resources: DOMAIN: 0000 0b base 000c0000 limit 07ffffff mem (fixed) constrain_resources: DOMAIN: 0000 0c base 00000510 limit 00000511 io (fixed) constrain_resources: DOMAIN: 0000 0d base 00005658 limit 00005658 io (fixed) constrain_resources: DOMAIN: 0000 0e base 0000ae00 limit 0000ae0f io (fixed) constrain_resources: DOMAIN: 0000 02 base fec00000 limit fecfffff mem (fixed) avoid_fixed_resources:@DOMAIN: 0000 10000000 base 00005659 limit 0000adff avoid_fixed_resources:@DOMAIN: 0000 10000100 base fc000000 limit febfffff Setting resources... DOMAIN: 0000 io: base:5659 size:50 align:6 gran:0 limit:adff PCI: 00:03.0 14 * [0x5800 - 0x583f] io PCI: 00:01.1 20 * [0x5840 - 0x584f] io DOMAIN: 0000 io: next_base: 5850 size: 50 align: 6 gran: 0 done DOMAIN: 0000 mem: base:fc000000 size:2071000 align:25 gran:0 limit:febfffff PCI: 00:02.0 10 * [0xfc000000 - 0xfdffffff] prefmem PCI: 00:03.0 30 * [0xfe000000 - 0xfe03ffff] mem PCI: 00:03.0 10 * [0xfe040000 - 0xfe05ffff] mem PCI: 00:02.0 30 * [0xfe060000 - 0xfe06ffff] mem PCI: 00:02.0 14 * [0xfe070000 - 0xfe070fff] mem DOMAIN: 0000 mem: next_base: fe071000 size: 2071000 align: 25 gran: 0 done Root Device assign_resources, bus 0 link: 0 DOMAIN: 0000 assign_resources, bus 0 link: 0 PCI: 00:01.1 20 <- [0x0000005840 - 0x000000584f] size 0x00000010 gran 0x04 io PCI: 00:02.0 10 <- [0x00fc000000 - 0x00fdffffff] size 0x02000000 gran 0x19 prefmem PCI: 00:02.0 14 <- [0x00fe070000 - 0x00fe070fff] size 0x00001000 gran 0x0c mem PCI: 00:02.0 30 <- [0x00fe060000 - 0x00fe06ffff] size 0x00010000 gran 0x10 romem PCI: 00:03.0 10 <- [0x00fe040000 - 0x00fe05ffff] size 0x00020000 gran 0x11 mem PCI: 00:03.0 14 <- [0x0000005800 - 0x000000583f] size 0x00000040 gran 0x06 io PCI: 00:03.0 30 <- [0x00fe000000 - 0x00fe03ffff] size 0x00040000 gran 0x12 romem DOMAIN: 0000 assign_resources, bus 0 link: 0 Root Device assign_resources, bus 0 link: 0 Done setting resources. Show resources in subtree (Root Device)...After assigning values. Root Device child on link 0 CPU_CLUSTER: 0 CPU_CLUSTER: 0 child on link 0 APIC: 00 APIC: 00 DOMAIN: 0000 child on link 0 PCI: 00:00.0 DOMAIN: 0000 resource base 5659 size 50 align 6 gran 0 limit adff flags 40040100 index 10000000 DOMAIN: 0000 resource base fc000000 size 2071000 align 25 gran 0 limit febfffff flags 40040200 index 10000100 DOMAIN: 0000 resource base 0 size a0000 align 0 gran 0 limit 0 flags e0004200 index a DOMAIN: 0000 resource base c0000 size 7f40000 align 0 gran 0 limit 0 flags e0004200 index b DOMAIN: 0000 resource base 510 size 2 align 0 gran 0 limit ffff flags e0000100 index c DOMAIN: 0000 resource base 5658 size 1 align 0 gran 0 limit ffff flags e0000100 index d DOMAIN: 0000 resource base ae00 size 10 align 0 gran 0 limit ffff flags e0000100 index e DOMAIN: 0000 resource base af00 size 20 align 0 gran 0 limit ffff flags e0000100 index f DOMAIN: 0000 resource base afe0 size 4 align 0 gran 0 limit ffff flags e0000100 index 10 DOMAIN: 0000 resource base fec00000 size 100000 align 0 gran 0 limit ffffffff flags e0000200 index 2 DOMAIN: 0000 resource base fee00000 size 10000 align 0 gran 0 limit ffffffff flags e0000200 index 3 PCI: 00:00.0 PCI: 00:01.0 PCI: 00:01.0 resource base 0 size 1000 align 0 gran 0 limit ffff flags c0000100 index 1 PCI: 00:01.0 resource base ff800000 size 800000 align 0 gran 0 limit 0 flags d0000200 index 2 PCI: 00:01.1 PCI: 00:01.1 resource base 5840 size 10 align 4 gran 4 limit 584f flags 60000100 index 20 PCI: 00:01.3 PCI: 00:01.3 resource base e400 size 40 align 0 gran 0 limit ffff flags d0000100 index 1 PCI: 00:01.3 resource base f00 size 10 align 0 gran 0 limit ffff flags d0000100 index 2 PCI: 00:02.0 PCI: 00:02.0 resource base fc000000 size 2000000 align 25 gran 25 limit fdffffff flags 60001200 index 10 PCI: 00:02.0 resource base fe070000 size 1000 align 12 gran 12 limit fe070fff flags 60000200 index 14 PCI: 00:02.0 resource base fe060000 size 10000 align 16 gran 16 limit fe06ffff flags 60002200 index 30 PCI: 00:03.0 PCI: 00:03.0 resource base fe040000 size 20000 align 17 gran 17 limit fe05ffff flags 60000200 index 10 PCI: 00:03.0 resource base 5800 size 40 align 6 gran 6 limit 583f flags 60000100 index 14 PCI: 00:03.0 resource base fe000000 size 40000 align 18 gran 18 limit fe03ffff flags 60002200 index 30 Done allocating resources.
注：
由于coreboot方面资料较少，笔者第一次尝试分析代码，还有众多未能参透的地方，难免出错。任何问题，欢迎一起交流学习。
李迟 2016.4.4 周一 清明节
